class Sequel::Database

A Database object represents a virtual connection to a database. The Database class is meant to be subclassed by database adapters in order to provide the functionality needed for executing queries.

Constants

OPTS

1 - Methods that execute queries and/or return results

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Constants

COLUMN_SCHEMA_DATETIME_TYPES
COLUMN_SCHEMA_STRING_TYPES
INTEGER1_MIN_MAX
INTEGER2_MIN_MAX
INTEGER3_MIN_MAX
INTEGER4_MIN_MAX
INTEGER8_MIN_MAX
UNSIGNED_INTEGER1_MIN_MAX
UNSIGNED_INTEGER2_MIN_MAX
UNSIGNED_INTEGER3_MIN_MAX
UNSIGNED_INTEGER4_MIN_MAX
UNSIGNED_INTEGER8_MIN_MAX

Attributes

cache_schema[RW]

Whether the schema should be cached for this database. True by default for performance, can be set to false to always issue a database query to get the schema.

prepared_statements[R]

The prepared statement object hash for this database, keyed by name symbol

Public Instance Methods

<<(sql) click to toggle source

Runs the supplied SQL statement string on the database server. Returns self so it can be safely chained:

DB << "UPDATE albums SET artist_id = NULL" << "DROP TABLE artists"
   # File lib/sequel/database/query.rb
25 def <<(sql)
26   run(sql)
27   self
28 end
call(ps_name, hash=OPTS, &block) click to toggle source

Call the prepared statement with the given name with the given hash of arguments.

DB[:items].where(id: 1).prepare(:first, :sa)
DB.call(:sa) # SELECT * FROM items WHERE id = 1
   # File lib/sequel/database/query.rb
35 def call(ps_name, hash=OPTS, &block)
36   prepared_statement(ps_name).call(hash, &block)
37 end
execute_ddl(sql, opts=OPTS, &block) click to toggle source

Method that should be used when submitting any DDL (Data Definition Language) SQL, such as create_table. By default, calls execute_dui. This method should not be called directly by user code.

   # File lib/sequel/database/query.rb
42 def execute_ddl(sql, opts=OPTS, &block)
43   execute_dui(sql, opts, &block)
44 end
execute_dui(sql, opts=OPTS, &block) click to toggle source

Method that should be used when issuing a DELETE or UPDATE statement. By default, calls execute. This method should not be called directly by user code.

   # File lib/sequel/database/query.rb
49 def execute_dui(sql, opts=OPTS, &block)
50   execute(sql, opts, &block)
51 end
execute_insert(sql, opts=OPTS, &block) click to toggle source

Method that should be used when issuing a INSERT statement. By default, calls execute_dui. This method should not be called directly by user code.

   # File lib/sequel/database/query.rb
56 def execute_insert(sql, opts=OPTS, &block)
57   execute_dui(sql, opts, &block)
58 end
get(*args, &block) click to toggle source

Returns a single value from the database, see Dataset#get.

DB.get(1) # SELECT 1
# => 1
DB.get{server_version.function} # SELECT server_version()
   # File lib/sequel/database/query.rb
65 def get(*args, &block)
66   @default_dataset.get(*args, &block)
67 end
run(sql, opts=OPTS) click to toggle source

Runs the supplied SQL statement string on the database server. Returns nil. Options:

:server

The server to run the SQL on.

DB.run("SET some_server_variable = 42")
   # File lib/sequel/database/query.rb
74 def run(sql, opts=OPTS)
75   sql = literal(sql) if sql.is_a?(SQL::PlaceholderLiteralString)
76   execute_ddl(sql, opts)
77   nil
78 end
schema(table, opts=OPTS) click to toggle source

Returns the schema for the given table as an array with all members being arrays of length 2, the first member being the column name, and the second member being a hash of column information. The table argument can also be a dataset, as long as it only has one table. Available options are:

:reload

Ignore any cached results, and get fresh information from the database.

:schema

An explicit schema to use. It may also be implicitly provided via the table name.

If schema parsing is supported by the database, the column information hash should contain at least the following entries:

:allow_null

Whether NULL is an allowed value for the column.

:db_type

The database type for the column, as a database specific string.

:default

The database default for the column, as a database specific string, or nil if there is no default value.

:primary_key

Whether the columns is a primary key column. If this column is not present, it means that primary key information is unavailable, not that the column is not a primary key.

:ruby_default

The database default for the column, as a ruby object. In many cases, complex database defaults cannot be parsed into ruby objects, in which case nil will be used as the value.

:type

A symbol specifying the type, such as :integer or :string.

Example:

DB.schema(:artists)
# [[:id,
#   {:type=>:integer,
#    :primary_key=>true,
#    :default=>"nextval('artist_id_seq'::regclass)",
#    :ruby_default=>nil,
#    :db_type=>"integer",
#    :allow_null=>false}],
#  [:name,
#   {:type=>:string,
#    :primary_key=>false,
#    :default=>nil,
#    :ruby_default=>nil,
#    :db_type=>"text",
#    :allow_null=>false}]]
    # File lib/sequel/database/query.rb
121 def schema(table, opts=OPTS)
122   raise(Error, 'schema parsing is not implemented on this database') unless supports_schema_parsing?
123 
124   opts = opts.dup
125   tab = if table.is_a?(Dataset)
126     o = table.opts
127     from = o[:from]
128     raise(Error, "can only parse the schema for a dataset with a single from table") unless from && from.length == 1 && !o.include?(:join) && !o.include?(:sql)
129     table.first_source_table
130   else
131     table
132   end
133 
134   qualifiers = split_qualifiers(tab)
135   table_name = qualifiers.pop
136   sch = qualifiers.pop
137   information_schema_schema = case qualifiers.length
138   when 1
139     Sequel.identifier(*qualifiers)
140   when 2
141     Sequel.qualify(*qualifiers)
142   end
143 
144   if table.is_a?(Dataset)
145     quoted_name = table.literal(tab)
146     opts[:dataset] = table
147   else
148     quoted_name = schema_utility_dataset.literal(table)
149   end
150 
151   opts[:schema] = sch if sch && !opts.include?(:schema)
152   opts[:information_schema_schema] = information_schema_schema if information_schema_schema && !opts.include?(:information_schema_schema)
153 
154   Sequel.synchronize{@schemas.delete(quoted_name)} if opts[:reload]
155   if v = Sequel.synchronize{@schemas[quoted_name]}
156     return v
157   end
158 
159   cols = schema_parse_table(table_name, opts)
160   raise(Error, "schema parsing returned no columns, table #{table_name.inspect} probably doesn't exist") if cols.nil? || cols.empty?
161 
162   primary_keys = 0
163   auto_increment_set = false
164   cols.each do |_,c|
165     auto_increment_set = true if c.has_key?(:auto_increment)
166     primary_keys += 1 if c[:primary_key]
167   end
168 
169   cols.each do |_,c|
170     c[:ruby_default] = column_schema_to_ruby_default(c[:default], c[:type]) unless c.has_key?(:ruby_default)
171     if c[:primary_key] && !auto_increment_set
172       # If adapter didn't set it, assume that integer primary keys are auto incrementing
173       c[:auto_increment] = primary_keys == 1 && !!(c[:db_type] =~ /int/io)
174     end
175     if !c[:max_length] && c[:type] == :string && (max_length = column_schema_max_length(c[:db_type]))
176       c[:max_length] = max_length
177     end
178     if !c[:max_value] && !c[:min_value]
179       min_max = case c[:type]
180       when :integer
181         column_schema_integer_min_max_values(c)
182       when :decimal
183         column_schema_decimal_min_max_values(c)
184       end
185       c[:min_value], c[:max_value] = min_max if min_max
186     end
187   end
188   schema_post_process(cols)
189 
190   Sequel.synchronize{@schemas[quoted_name] = cols} if cache_schema
191   cols
192 end
table_exists?(name) click to toggle source

Returns true if a table with the given name exists. This requires a query to the database.

DB.table_exists?(:foo) # => false
# SELECT NULL FROM foo LIMIT 1

Note that since this does a SELECT from the table, it can give false negatives if you don’t have permission to SELECT from the table.

    # File lib/sequel/database/query.rb
202 def table_exists?(name)
203   sch, table_name = schema_and_table(name)
204   name = SQL::QualifiedIdentifier.new(sch, table_name) if sch
205   ds = from(name)
206   transaction(:savepoint=>:only){_table_exists?(ds)}
207   true
208 rescue DatabaseError
209   false
210 end

Private Instance Methods

_metadata_dataset() click to toggle source

Uncached version of metadata_dataset, designed for overriding.

    # File lib/sequel/database/query.rb
362 def _metadata_dataset
363   dataset
364 end
_table_exists?(ds) click to toggle source

Should raise an error if the table doesn’t not exist, and not raise an error if the table does exist.

    # File lib/sequel/database/query.rb
216 def _table_exists?(ds)
217   ds.get(SQL::AliasedExpression.new(Sequel::NULL, :nil))
218 end
column_schema_decimal_min_max_values(column) click to toggle source

Look at the db_type and guess the minimum and maximum decimal values for the column.

    # File lib/sequel/database/query.rb
323 def column_schema_decimal_min_max_values(column)
324   if column[:column_size] && column[:scale]
325     precision = column[:column_size]
326     scale = column[:scale]
327   elsif /\((\d+)(?:,\s*(-?\d+))?\)/ =~ column[:db_type]
328     precision = $1.to_i
329     scale = $2.to_i if $2
330   end
331 
332   if precision
333     limit = BigDecimal("9" * precision)
334     if scale
335       limit /= 10**(scale)
336     end
337     [-limit, limit]
338   end
339 end
column_schema_default_string_type?(type) click to toggle source

Whether the type should be treated as a string type when parsing the column schema default value.

    # File lib/sequel/database/query.rb
222 def column_schema_default_string_type?(type)
223   COLUMN_SCHEMA_STRING_TYPES.include?(type)
224 end
column_schema_default_to_ruby_value(default, type) click to toggle source

Transform the given normalized default string into a ruby object for the given type.

    # File lib/sequel/database/query.rb
228 def column_schema_default_to_ruby_value(default, type)
229   case type
230   when :boolean
231     case default 
232     when /[f0]/i
233       false
234     when /[t1]/i
235       true
236     end
237   when :string, :enum, :set, :interval
238     default
239   when :blob
240     Sequel::SQL::Blob.new(default)
241   when :integer
242     Integer(default)
243   when :float
244     Float(default)
245   when :date
246     Sequel.string_to_date(default)
247   when :datetime
248     Sequel.string_to_datetime(default)
249   when :time
250     Sequel.string_to_time(default)
251   when :decimal
252     BigDecimal(default)
253   end
254 end
column_schema_integer_min_max_values(column) click to toggle source

Look at the db_type and guess the minimum and maximum integer values for the column.

    # File lib/sequel/database/query.rb
297 def column_schema_integer_min_max_values(column)
298   db_type = column[:db_type]
299   if /decimal|numeric|number/i =~ db_type
300     if min_max = column_schema_decimal_min_max_values(column)
301       min_max.map!(&:to_i)
302     end
303     return min_max
304   end
305 
306   unsigned = /unsigned/i =~ db_type
307   case db_type
308   when /big|int8/i
309     unsigned ? UNSIGNED_INTEGER8_MIN_MAX : INTEGER8_MIN_MAX
310   when /medium/i
311     unsigned ? UNSIGNED_INTEGER3_MIN_MAX : INTEGER3_MIN_MAX
312   when /small|int2/i
313     unsigned ? UNSIGNED_INTEGER2_MIN_MAX : INTEGER2_MIN_MAX
314   when /tiny/i
315     (unsigned || column_schema_tinyint_type_is_unsigned?) ? UNSIGNED_INTEGER1_MIN_MAX : INTEGER1_MIN_MAX
316   else
317     unsigned ? UNSIGNED_INTEGER4_MIN_MAX : INTEGER4_MIN_MAX
318   end
319 end
column_schema_max_length(db_type) click to toggle source

Look at the db_type and guess the maximum length of the column. This assumes types such as varchar(255).

    # File lib/sequel/database/query.rb
348 def column_schema_max_length(db_type)
349   if db_type =~ /\((\d+)\)/
350     $1.to_i
351   end
352 end
column_schema_normalize_default(default, type) click to toggle source

Normalize the default value string for the given type and return the normalized value.

    # File lib/sequel/database/query.rb
258 def column_schema_normalize_default(default, type)
259   if column_schema_default_string_type?(type)
260     return unless m = /\A'(.*)'\z/.match(default)
261     m[1].gsub("''", "'")
262   else
263     default
264   end
265 end
column_schema_tinyint_type_is_unsigned?() click to toggle source

Whether the tinyint type (if supported by the database) is unsigned by default.

    # File lib/sequel/database/query.rb
342 def column_schema_tinyint_type_is_unsigned?
343   false
344 end
column_schema_to_ruby_default(default, type) click to toggle source

Convert the given default, which should be a database specific string, into a ruby object.

    # File lib/sequel/database/query.rb
269 def column_schema_to_ruby_default(default, type)
270   return default unless default.is_a?(String)
271   if COLUMN_SCHEMA_DATETIME_TYPES.include?(type)
272     if /now|today|CURRENT|getdate|\ADate\(\)\z/i.match(default)
273       if type == :date
274         return Sequel::CURRENT_DATE
275       else
276         return Sequel::CURRENT_TIMESTAMP
277       end
278     end
279   end
280   default = column_schema_normalize_default(default, type)
281   column_schema_default_to_ruby_value(default, type) rescue nil
282 end
input_identifier_meth(ds=nil) click to toggle source

Return a Method object for the dataset’s output_identifier_method. Used in metadata parsing to make sure the returned information is in the correct format.

    # File lib/sequel/database/query.rb
357 def input_identifier_meth(ds=nil)
358   (ds || dataset).method(:input_identifier)
359 end
metadata_dataset() click to toggle source

Return a dataset that uses the default identifier input and output methods for this database. Used when parsing metadata so that column symbols are returned as expected.

    # File lib/sequel/database/query.rb
369 def metadata_dataset
370   @metadata_dataset ||= _metadata_dataset
371 end
output_identifier_meth(ds=nil) click to toggle source

Return a Method object for the dataset’s output_identifier_method. Used in metadata parsing to make sure the returned information is in the correct format.

    # File lib/sequel/database/query.rb
376 def output_identifier_meth(ds=nil)
377   (ds || dataset).method(:output_identifier)
378 end
remove_cached_schema(table) click to toggle source

Remove the cached schema for the given schema name

    # File lib/sequel/database/query.rb
381 def remove_cached_schema(table)
382   cache = @default_dataset.send(:cache)
383   Sequel.synchronize{cache.clear}
384   k = quote_schema_table(table)
385   Sequel.synchronize{@schemas.delete(k)}
386 end
schema_column_type(db_type) click to toggle source

Match the database’s column type to a ruby type via a regular expression, and return the ruby type as a symbol such as :integer or :string.

    # File lib/sequel/database/query.rb
391 def schema_column_type(db_type)
392   case db_type
393   when /\A(character( varying)?|n?(var)?char|n?text|string|clob)/io
394     :string
395   when /\A(int(eger)?|(big|small|tiny)int)/io
396     :integer
397   when /\Adate\z/io
398     :date
399   when /\A((small)?datetime|timestamp(\(\d\))?( with(out)? time zone)?)\z/io
400     :datetime
401   when /\Atime( with(out)? time zone)?\z/io
402     :time
403   when /\A(bool(ean)?)\z/io
404     :boolean
405   when /\A(real|float( unsigned)?|double( precision)?|double\(\d+,\d+\)( unsigned)?)\z/io
406     :float
407   when /\A(?:(?:(?:num(?:ber|eric)?|decimal)(?:\(\d+,\s*(-?\d+|false|true)\))?))\z/io
408     $1 && ['0', 'false'].include?($1) ? :integer : :decimal
409   when /bytea|blob|image|(var)?binary/io
410     :blob
411   when /\Aenum/io
412     :enum
413   end
414 end
schema_post_process(cols) click to toggle source

Post process the schema values.

    # File lib/sequel/database/query.rb
417 def schema_post_process(cols)
418   # :nocov:
419   if RUBY_VERSION >= '2.5'
420   # :nocov:
421     cols.each do |_, h|
422       db_type = h[:db_type]
423       if db_type.is_a?(String)
424         h[:db_type] = -db_type
425       end
426     end
427   end
428 
429   cols.each do |_,c|
430     c.each_value do |val|
431       val.freeze if val.is_a?(String)
432     end
433   end
434 end

2 - Methods that modify the database schema

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Constants

COLUMN_DEFINITION_ORDER

The order of column modifiers to use when defining a column.

COMBINABLE_ALTER_TABLE_OPS

The alter table operations that are combinable.

Public Instance Methods

add_column(table, *args) click to toggle source

Adds a column to the specified table. This method expects a column name, a datatype and optionally a hash with additional constraints and options:

DB.add_column :items, :name, String, unique: true, null: false
DB.add_column :items, :category, String, default: 'ruby'

See alter_table.

   # File lib/sequel/database/schema_methods.rb
25 def add_column(table, *args)
26   alter_table(table) {add_column(*args)}
27 end
add_index(table, columns, options=OPTS) click to toggle source

Adds an index to a table for the given columns:

DB.add_index :posts, :title
DB.add_index :posts, [:author, :title], unique: true

Options:

:ignore_errors

Ignore any DatabaseErrors that are raised

:name

Name to use for index instead of default

See alter_table.

   # File lib/sequel/database/schema_methods.rb
40 def add_index(table, columns, options=OPTS)
41   e = options[:ignore_errors]
42   begin
43     alter_table(table){add_index(columns, options)}
44   rescue DatabaseError
45     raise unless e
46   end
47   nil
48 end
alter_table(name, &block) click to toggle source

Alters the given table with the specified block. Example:

DB.alter_table :items do
  add_column :category, String, default: 'ruby'
  drop_column :category
  rename_column :cntr, :counter
  set_column_type :value, Float
  set_column_default :value, 4.2
  add_index [:group, :category]
  drop_index [:group, :category]
end

Note that add_column accepts all the options available for column definitions using create_table, and add_index accepts all the options available for index definition.

See Schema::AlterTableGenerator and the Migrations guide.

   # File lib/sequel/database/schema_methods.rb
67 def alter_table(name, &block)
68   generator = alter_table_generator(&block)
69   remove_cached_schema(name)
70   apply_alter_table_generator(name, generator)
71   nil
72 end
alter_table_generator(&block) click to toggle source

Return a new Schema::AlterTableGenerator instance with the receiver as the database and the given block.

   # File lib/sequel/database/schema_methods.rb
76 def alter_table_generator(&block)
77   alter_table_generator_class.new(self, &block)
78 end
create_join_table(hash, options=OPTS) click to toggle source

Create a join table using a hash of foreign keys to referenced table names. Example:

create_join_table(cat_id: :cats, dog_id: :dogs)
# CREATE TABLE cats_dogs (
#  cat_id integer NOT NULL REFERENCES cats,
#  dog_id integer NOT NULL REFERENCES dogs,
#  PRIMARY KEY (cat_id, dog_id)
# )
# CREATE INDEX cats_dogs_dog_id_cat_id_index ON cats_dogs(dog_id, cat_id)

The primary key and index are used so that almost all operations on the table can benefit from one of the two indexes, and the primary key ensures that entries in the table are unique, which is the typical desire for a join table.

The default table name this will create is the sorted version of the two hash values, joined by an underscore. So the following two method calls create the same table:

create_join_table(cat_id: :cats, dog_id: :dogs) # cats_dogs
create_join_table(dog_id: :dogs, cat_id: :cats) # cats_dogs

You can provide column options by making the values in the hash be option hashes, so long as the option hashes have a :table entry giving the table referenced:

create_join_table(cat_id: {table: :cats, type: :Bignum}, dog_id: :dogs)

You can provide a second argument which is a table options hash:

create_join_table({cat_id: :cats, dog_id: :dogs}, temp: true)

Some table options are handled specially:

:index_options

The options to pass to the index

:name

The name of the table to create

:no_index

Set to true not to create the second index.

:no_primary_key

Set to true to not create the primary key.

    # File lib/sequel/database/schema_methods.rb
119 def create_join_table(hash, options=OPTS)
120   keys = hash.keys.sort
121   create_table(join_table_name(hash, options), options) do
122     keys.each do |key|
123       v = hash[key]
124       unless v.is_a?(Hash)
125         v = {:table=>v}
126       end
127       v[:null] = false unless v.has_key?(:null)
128       foreign_key(key, v)
129     end
130     primary_key(keys) unless options[:no_primary_key]
131     index(keys.reverse, options[:index_options] || OPTS) unless options[:no_index]
132   end
133   nil
134 end
create_join_table!(hash, options=OPTS) click to toggle source

Forcibly create a join table, attempting to drop it if it already exists, then creating it.

    # File lib/sequel/database/schema_methods.rb
137 def create_join_table!(hash, options=OPTS)
138   drop_table?(join_table_name(hash, options))
139   create_join_table(hash, options)
140 end
create_join_table?(hash, options=OPTS) click to toggle source

Creates the join table unless it already exists.

    # File lib/sequel/database/schema_methods.rb
143 def create_join_table?(hash, options=OPTS)
144   if supports_create_table_if_not_exists? && options[:no_index]
145     create_join_table(hash, options.merge(:if_not_exists=>true))
146   elsif !table_exists?(join_table_name(hash, options))
147     create_join_table(hash, options)
148   end
149 end
create_or_replace_view(name, source, options = OPTS) click to toggle source

Creates a view, replacing a view with the same name if one already exists.

DB.create_or_replace_view(:some_items, "SELECT * FROM items WHERE price < 100")
DB.create_or_replace_view(:some_items, DB[:items].where(category: 'ruby'))

For databases where replacing a view is not natively supported, support is emulated by dropping a view with the same name before creating the view.

    # File lib/sequel/database/schema_methods.rb
254 def create_or_replace_view(name, source, options = OPTS)
255   if supports_create_or_replace_view? && !options[:materialized]
256     options = options.merge(:replace=>true)
257   else
258     swallow_database_error{drop_view(name, options)}
259   end
260 
261   create_view(name, source, options)
262   nil
263 end
create_table(name, options=OPTS, &block) click to toggle source

Creates a table with the columns given in the provided block:

DB.create_table :posts do
  primary_key :id
  column :title, String
  String :content
  index :title
end

General options:

:as

Create the table using the value, which should be either a dataset or a literal SQL string. If this option is used, a block should not be given to the method.

:ignore_index_errors

Ignore any errors when creating indexes.

:temp

Create the table as a temporary table.

MySQL specific options:

:charset

The character set to use for the table.

:collate

The collation to use for the table.

:engine

The table engine to use for the table.

PostgreSQL specific options:

:on_commit

Either :preserve_rows (default), :drop or :delete_rows. Should only be specified when creating a temporary table.

:foreign

Create a foreign table. The value should be the name of the foreign server that was specified in CREATE SERVER.

:inherits

Inherit from a different table. An array can be specified to inherit from multiple tables.

:unlogged

Create the table as an unlogged table.

:options

The OPTIONS clause to use for foreign tables. Should be a hash where keys are option names and values are option values. Note that option names are unquoted, so you should not use untrusted keys.

:tablespace

The tablespace to use for the table.

SQLite specific options:

:strict

Create a STRICT table, which checks that the values for the columns are the correct type (similar to all other SQL databases). Note that when using this option, all column types used should be one of the following: int, integer, real, text, blob, and any. The any type is treated like a SQLite column in a non-strict table, allowing any type of data to be stored. This option is supported on SQLite 3.37.0+.

:without_rowid

Create a WITHOUT ROWID table. Every row in SQLite has a special ‘rowid’ column, that uniquely identifies that row within the table. If this option is used, the ‘rowid’ column is omitted, which can sometimes provide some space and speed advantages. Note that you must then provide an explicit primary key when you create the table. This option is supported on SQLite 3.8.2+.

See Schema::CreateTableGenerator and the “Schema Modification” guide.

    # File lib/sequel/database/schema_methods.rb
202 def create_table(name, options=OPTS, &block)
203   remove_cached_schema(name)
204   if sql = options[:as]
205     raise(Error, "can't provide both :as option and block to create_table") if block
206     create_table_as(name, sql, options)
207   else
208     generator = options[:generator] || create_table_generator(&block)
209     create_table_from_generator(name, generator, options)
210     create_table_indexes_from_generator(name, generator, options)
211   end
212   nil
213 end
create_table!(name, options=OPTS, &block) click to toggle source

Forcibly create a table, attempting to drop it if it already exists, then creating it.

DB.create_table!(:a){Integer :a} 
# SELECT NULL FROM a LIMIT 1 -- check existence
# DROP TABLE a -- drop table if already exists
# CREATE TABLE a (a integer)
    # File lib/sequel/database/schema_methods.rb
221 def create_table!(name, options=OPTS, &block)
222   drop_table?(name)
223   create_table(name, options, &block)
224 end
create_table?(name, options=OPTS, &block) click to toggle source

Creates the table unless the table already exists.

DB.create_table?(:a){Integer :a} 
# SELECT NULL FROM a LIMIT 1 -- check existence
# CREATE TABLE a (a integer) -- if it doesn't already exist
    # File lib/sequel/database/schema_methods.rb
231 def create_table?(name, options=OPTS, &block)
232   options = options.dup
233   generator = options[:generator] ||= create_table_generator(&block)
234   if generator.indexes.empty? && supports_create_table_if_not_exists?
235     create_table(name, options.merge!(:if_not_exists=>true))
236   elsif !table_exists?(name)
237     create_table(name, options)
238   end
239 end
create_table_generator(&block) click to toggle source

Return a new Schema::CreateTableGenerator instance with the receiver as the database and the given block.

    # File lib/sequel/database/schema_methods.rb
243 def create_table_generator(&block)
244   create_table_generator_class.new(self, &block)
245 end
create_view(name, source, options = OPTS) click to toggle source

Creates a view based on a dataset or an SQL string:

DB.create_view(:cheap_items, "SELECT * FROM items WHERE price < 100")
# CREATE VIEW cheap_items AS
# SELECT * FROM items WHERE price < 100

DB.create_view(:ruby_items, DB[:items].where(category: 'ruby'))
# CREATE VIEW ruby_items AS
# SELECT * FROM items WHERE (category = 'ruby')

DB.create_view(:checked_items, DB[:items].where(:foo), check: true)
# CREATE VIEW checked_items AS
# SELECT * FROM items WHERE foo
# WITH CHECK OPTION

DB.create_view(:bar_items, DB[:items].select(:foo), columns: [:bar])
# CREATE VIEW bar_items (bar) AS
# SELECT foo FROM items

Options:

:columns

The column names to use for the view. If not given, automatically determined based on the input dataset.

:check

Adds a WITH CHECK OPTION clause, so that attempting to modify rows in the underlying table that would not be returned by the view is not allowed. This can be set to :local to use WITH LOCAL CHECK OPTION.

PostgreSQL/SQLite specific option:

:temp

Create a temporary view, automatically dropped on disconnect.

PostgreSQL specific options:

:materialized

Creates a materialized view, similar to a regular view, but backed by a physical table.

:recursive

Creates a recursive view. As columns must be specified for recursive views, you can also set them as the value of this option. Since a recursive view requires a union that isn’t in a subquery, if you are providing a Dataset as the source argument, if should probably call the union method with the all: true and from_self: false options.

:security_invoker

Set the security_invoker property on the view, making the access to the view use the current user’s permissions, instead of the view owner’s permissions.

:tablespace

The tablespace to use for materialized views.

    # File lib/sequel/database/schema_methods.rb
308 def create_view(name, source, options = OPTS)
309   execute_ddl(create_view_sql(name, source, options))
310   remove_cached_schema(name)
311   nil
312 end
drop_column(table, *args) click to toggle source

Removes a column from the specified table:

DB.drop_column :items, :category

See alter_table.

    # File lib/sequel/database/schema_methods.rb
319 def drop_column(table, *args)
320   alter_table(table) {drop_column(*args)}
321 end
drop_index(table, columns, options=OPTS) click to toggle source

Removes an index for the given table and column(s):

DB.drop_index :posts, :title
DB.drop_index :posts, [:author, :title]

See alter_table.

    # File lib/sequel/database/schema_methods.rb
329 def drop_index(table, columns, options=OPTS)
330   alter_table(table){drop_index(columns, options)}
331 end
drop_join_table(hash, options=OPTS) click to toggle source

Drop the join table that would have been created with the same arguments to create_join_table:

drop_join_table(cat_id: :cats, dog_id: :dogs)
# DROP TABLE cats_dogs
    # File lib/sequel/database/schema_methods.rb
338 def drop_join_table(hash, options=OPTS)
339   drop_table(join_table_name(hash, options), options)
340 end
drop_table(*names) click to toggle source

Drops one or more tables corresponding to the given names:

DB.drop_table(:posts) # DROP TABLE posts
DB.drop_table(:posts, :comments)
DB.drop_table(:posts, :comments, cascade: true)
    # File lib/sequel/database/schema_methods.rb
347 def drop_table(*names)
348   options = names.last.is_a?(Hash) ? names.pop : OPTS 
349   names.each do |n|
350     execute_ddl(drop_table_sql(n, options))
351     remove_cached_schema(n)
352   end
353   nil
354 end
drop_table?(*names) click to toggle source

Drops the table if it already exists. If it doesn’t exist, does nothing.

DB.drop_table?(:a)
# SELECT NULL FROM a LIMIT 1 -- check existence
# DROP TABLE a -- if it already exists
    # File lib/sequel/database/schema_methods.rb
362 def drop_table?(*names)
363   options = names.last.is_a?(Hash) ? names.pop : OPTS
364   if supports_drop_table_if_exists?
365     options = options.merge(:if_exists=>true)
366     names.each do |name|
367       drop_table(name, options)
368     end
369   else
370     names.each do |name|
371       drop_table(name, options) if table_exists?(name)
372     end
373   end
374   nil
375 end
drop_view(*names) click to toggle source

Drops one or more views corresponding to the given names:

DB.drop_view(:cheap_items)
DB.drop_view(:cheap_items, :pricey_items)
DB.drop_view(:cheap_items, :pricey_items, cascade: true)
DB.drop_view(:cheap_items, :pricey_items, if_exists: true)

Options:

:cascade

Also drop objects depending on this view.

:if_exists

Do not raise an error if the view does not exist.

PostgreSQL specific options:

:materialized

Drop a materialized view.

    # File lib/sequel/database/schema_methods.rb
390 def drop_view(*names)
391   options = names.last.is_a?(Hash) ? names.pop : OPTS
392   names.each do |n|
393     execute_ddl(drop_view_sql(n, options))
394     remove_cached_schema(n)
395   end
396   nil
397 end
rename_column(table, *args) click to toggle source

Renames a column in the specified table. This method expects the current column name and the new column name:

DB.rename_column :items, :cntr, :counter

See alter_table.

    # File lib/sequel/database/schema_methods.rb
416 def rename_column(table, *args)
417   alter_table(table) {rename_column(*args)}
418 end
rename_table(name, new_name) click to toggle source

Renames a table:

DB.tables #=> [:items]
DB.rename_table :items, :old_items
DB.tables #=> [:old_items]
    # File lib/sequel/database/schema_methods.rb
404 def rename_table(name, new_name)
405   execute_ddl(rename_table_sql(name, new_name))
406   remove_cached_schema(name)
407   nil
408 end
set_column_default(table, *args) click to toggle source

Sets the default value for the given column in the given table:

DB.set_column_default :items, :category, 'perl!'

See alter_table.

    # File lib/sequel/database/schema_methods.rb
425 def set_column_default(table, *args)
426   alter_table(table) {set_column_default(*args)}
427 end
set_column_type(table, *args) click to toggle source

Set the data type for the given column in the given table:

DB.set_column_type :items, :price, :float

See alter_table.

    # File lib/sequel/database/schema_methods.rb
434 def set_column_type(table, *args)
435   alter_table(table) {set_column_type(*args)}
436 end

Private Instance Methods

alter_table_add_column_sql(table, op) click to toggle source
    # File lib/sequel/database/schema_methods.rb
474 def alter_table_add_column_sql(table, op)
475   "ADD COLUMN #{column_definition_sql(op)}"
476 end
alter_table_add_constraint_sql(table, op) click to toggle source
    # File lib/sequel/database/schema_methods.rb
498 def alter_table_add_constraint_sql(table, op)
499   "ADD #{constraint_definition_sql(op)}"
500 end
alter_table_drop_column_sql(table, op) click to toggle source
    # File lib/sequel/database/schema_methods.rb
478 def alter_table_drop_column_sql(table, op)
479   "DROP COLUMN #{quote_identifier(op[:name])}#{' CASCADE' if op[:cascade]}"
480 end
alter_table_drop_constraint_sql(table, op) click to toggle source
    # File lib/sequel/database/schema_methods.rb
502 def alter_table_drop_constraint_sql(table, op)
503   quoted_name = quote_identifier(op[:name]) if op[:name]
504   if op[:type] == :foreign_key
505     quoted_name ||= quote_identifier(foreign_key_name(table, op[:columns]))
506   end
507   "DROP CONSTRAINT #{quoted_name}#{' CASCADE' if op[:cascade]}"
508 end
alter_table_generator_class() click to toggle source

The class used for alter_table generators.

    # File lib/sequel/database/schema_methods.rb
459 def alter_table_generator_class
460   Schema::AlterTableGenerator
461 end
alter_table_op_sql(table, op) click to toggle source

SQL fragment for given alter table operation.

    # File lib/sequel/database/schema_methods.rb
464 def alter_table_op_sql(table, op)
465   meth = "alter_table_#{op[:op]}_sql"
466   if respond_to?(meth, true)
467     # Allow calling private methods as alter table op sql methods are private
468     send(meth, table, op)
469   else
470     raise Error, "Unsupported ALTER TABLE operation: #{op[:op]}"
471   end
472 end
alter_table_rename_column_sql(table, op) click to toggle source
    # File lib/sequel/database/schema_methods.rb
482 def alter_table_rename_column_sql(table, op)
483   "RENAME COLUMN #{quote_identifier(op[:name])} TO #{quote_identifier(op[:new_name])}"
484 end
alter_table_set_column_default_sql(table, op) click to toggle source
    # File lib/sequel/database/schema_methods.rb
490 def alter_table_set_column_default_sql(table, op)
491   "ALTER COLUMN #{quote_identifier(op[:name])} SET DEFAULT #{literal(op[:default])}"
492 end
alter_table_set_column_null_sql(table, op) click to toggle source
    # File lib/sequel/database/schema_methods.rb
494 def alter_table_set_column_null_sql(table, op)
495   "ALTER COLUMN #{quote_identifier(op[:name])} #{op[:null] ? 'DROP' : 'SET'} NOT NULL"
496 end
alter_table_set_column_type_sql(table, op) click to toggle source
    # File lib/sequel/database/schema_methods.rb
486 def alter_table_set_column_type_sql(table, op)
487   "ALTER COLUMN #{quote_identifier(op[:name])} TYPE #{type_literal(op)}"
488 end
alter_table_sql(table, op) click to toggle source

The SQL to execute to modify the table. op should be one of the operations returned by the AlterTableGenerator.

    # File lib/sequel/database/schema_methods.rb
512 def alter_table_sql(table, op)
513   case op[:op]
514   when :add_index
515     index_definition_sql(table, op)
516   when :drop_index
517     drop_index_sql(table, op)
518   else
519     if sql = alter_table_op_sql(table, op)
520       "ALTER TABLE #{quote_schema_table(table)} #{sql}"
521     end
522   end
523 end
alter_table_sql_list(table, operations) click to toggle source

Array of SQL statements used to modify the table, corresponding to changes specified by the operations.

    # File lib/sequel/database/schema_methods.rb
527 def alter_table_sql_list(table, operations)
528   if supports_combining_alter_table_ops?
529     grouped_ops = []
530     last_combinable = false
531     operations.each do |op|
532       if combinable_alter_table_op?(op)
533         if sql = alter_table_op_sql(table, op)
534           grouped_ops << [] unless last_combinable
535           grouped_ops.last << sql
536           last_combinable = true
537         end
538       elsif sql = alter_table_sql(table, op)
539         Array(sql).each{|s| grouped_ops << s}
540         last_combinable = false
541       end
542     end
543     grouped_ops.map do |gop|
544       if gop.is_a?(Array)
545         "ALTER TABLE #{quote_schema_table(table)} #{gop.join(', ')}"
546       else
547         gop
548       end
549     end
550   else
551     operations.map{|op| alter_table_sql(table, op)}.flatten.compact
552   end
553 end
apply_alter_table(name, ops) click to toggle source

Apply the changes in the given alter table ops to the table given by name.

    # File lib/sequel/database/schema_methods.rb
441 def apply_alter_table(name, ops)
442   alter_table_sql_list(name, ops).each{|sql| execute_ddl(sql)}
443 end
apply_alter_table_generator(name, generator) click to toggle source

Apply the operations in the given generator to the table given by name.

    # File lib/sequel/database/schema_methods.rb
446 def apply_alter_table_generator(name, generator)
447   ops = generator.operations
448 
449   unless can_add_primary_key_constraint_on_nullable_columns?
450     if add_pk = ops.find{|op| op[:op] == :add_constraint && op[:type] == :primary_key}
451       ops = add_pk[:columns].map{|column| {:op => :set_column_null, :name => column, :null => false}} + ops
452     end
453   end
454 
455   apply_alter_table(name, ops)
456 end
auto_increment_sql() click to toggle source

The SQL string specify the autoincrement property, generally used by primary keys.

    # File lib/sequel/database/schema_methods.rb
557 def auto_increment_sql
558   'AUTOINCREMENT'
559 end
column_definition_auto_increment_sql(sql, column) click to toggle source

Add auto increment SQL fragment to column creation SQL.

    # File lib/sequel/database/schema_methods.rb
575 def column_definition_auto_increment_sql(sql, column)
576   sql << " #{auto_increment_sql}" if column[:auto_increment]
577 end
column_definition_collate_sql(sql, column) click to toggle source

Add collate SQL fragment to column creation SQL.

    # File lib/sequel/database/schema_methods.rb
580 def column_definition_collate_sql(sql, column)
581   if collate = column[:collate]
582     sql << " COLLATE #{collate}"
583   end
584 end
column_definition_default_sql(sql, column) click to toggle source

Add default SQL fragment to column creation SQL.

    # File lib/sequel/database/schema_methods.rb
587 def column_definition_default_sql(sql, column)
588   sql << " DEFAULT #{literal(column[:default])}" if column.include?(:default)
589 end
column_definition_null_sql(sql, column) click to toggle source

Add null/not null SQL fragment to column creation SQL.

    # File lib/sequel/database/schema_methods.rb
592 def column_definition_null_sql(sql, column)
593   null = column.fetch(:null, column[:allow_null])
594   if null.nil? && !can_add_primary_key_constraint_on_nullable_columns? && column[:primary_key]
595     null = false
596   end
597 
598   case null
599   when false
600     sql << ' NOT NULL'
601   when true
602     sql << ' NULL'
603   end
604 end
column_definition_order() click to toggle source

The order of the column definition, as an array of symbols.

    # File lib/sequel/database/schema_methods.rb
562 def column_definition_order
563   COLUMN_DEFINITION_ORDER
564 end
column_definition_primary_key_sql(sql, column) click to toggle source

Add primary key SQL fragment to column creation SQL.

    # File lib/sequel/database/schema_methods.rb
607 def column_definition_primary_key_sql(sql, column)
608   if column[:primary_key]
609     if name = column[:primary_key_constraint_name]
610       sql << " CONSTRAINT #{quote_identifier(name)}"
611     end
612     sql << " " << primary_key_constraint_sql_fragment(column)
613     constraint_deferrable_sql_append(sql, column[:primary_key_deferrable])
614   end
615 end
column_definition_references_sql(sql, column) click to toggle source

Add foreign key reference SQL fragment to column creation SQL.

    # File lib/sequel/database/schema_methods.rb
618 def column_definition_references_sql(sql, column)
619   if column[:table]
620     if name = column[:foreign_key_constraint_name]
621      sql << " CONSTRAINT #{quote_identifier(name)}"
622     end
623     sql << column_references_column_constraint_sql(column)
624   end
625 end
column_definition_sql(column) click to toggle source

SQL fragment containing the column creation SQL for the given column.

    # File lib/sequel/database/schema_methods.rb
567 def column_definition_sql(column)
568   sql = String.new
569   sql << "#{quote_identifier(column[:name])} #{type_literal(column)}"
570   column_definition_order.each{|m| send(:"column_definition_#{m}_sql", sql, column)}
571   sql
572 end
column_definition_unique_sql(sql, column) click to toggle source

Add unique constraint SQL fragment to column creation SQL.

    # File lib/sequel/database/schema_methods.rb
628 def column_definition_unique_sql(sql, column)
629   if column[:unique]
630     if name = column[:unique_constraint_name]
631       sql << " CONSTRAINT #{quote_identifier(name)}"
632     end
633     sql << ' ' << unique_constraint_sql_fragment(column)
634     constraint_deferrable_sql_append(sql, column[:unique_deferrable])
635   end
636 end
column_list_sql(generator) click to toggle source

SQL for all given columns, used inside a CREATE TABLE block.

    # File lib/sequel/database/schema_methods.rb
639 def column_list_sql(generator)
640   (generator.columns.map{|c| column_definition_sql(c)} + generator.constraints.map{|c| constraint_definition_sql(c)}).join(', ')
641 end
column_references_column_constraint_sql(column) click to toggle source

SQL fragment for column foreign key references (column constraints)

    # File lib/sequel/database/schema_methods.rb
644 def column_references_column_constraint_sql(column)
645   column_references_sql(column)
646 end
column_references_sql(column) click to toggle source

SQL fragment for column foreign key references

    # File lib/sequel/database/schema_methods.rb
649 def column_references_sql(column)
650   sql = String.new
651   sql << " REFERENCES #{quote_schema_table(column[:table])}"
652   sql << "(#{Array(column[:key]).map{|x| quote_identifier(x)}.join(', ')})" if column[:key]
653   sql << " ON DELETE #{on_delete_clause(column[:on_delete])}" if column[:on_delete]
654   sql << " ON UPDATE #{on_update_clause(column[:on_update])}" if column[:on_update]
655   constraint_deferrable_sql_append(sql, column[:deferrable])
656   sql
657 end
column_references_table_constraint_sql(constraint) click to toggle source

SQL fragment for table foreign key references (table constraints)

    # File lib/sequel/database/schema_methods.rb
660 def column_references_table_constraint_sql(constraint)
661   "FOREIGN KEY #{literal(constraint[:columns])}#{column_references_sql(constraint)}"
662 end
combinable_alter_table_op?(op) click to toggle source

Whether the given alter table operation is combinable.

    # File lib/sequel/database/schema_methods.rb
665 def combinable_alter_table_op?(op)
666   COMBINABLE_ALTER_TABLE_OPS.include?(op[:op])
667 end
constraint_deferrable_sql_append(sql, defer) click to toggle source

SQL fragment specifying the deferrable constraint attributes.

    # File lib/sequel/database/schema_methods.rb
694 def constraint_deferrable_sql_append(sql, defer)
695   case defer
696   when nil
697   when false
698     sql << ' NOT DEFERRABLE'
699   when :immediate
700     sql << ' DEFERRABLE INITIALLY IMMEDIATE'
701   else
702     sql << ' DEFERRABLE INITIALLY DEFERRED'
703   end
704 end
constraint_definition_sql(constraint) click to toggle source

SQL fragment specifying a constraint on a table.

    # File lib/sequel/database/schema_methods.rb
670 def constraint_definition_sql(constraint)
671   sql = String.new
672   sql << "CONSTRAINT #{quote_identifier(constraint[:name])} " if constraint[:name] 
673   case constraint[:type]
674   when :check
675     check = constraint[:check]
676     check = check.first if check.is_a?(Array) && check.length == 1
677     check = filter_expr(check)
678     check = "(#{check})" unless check[0..0] == '(' && check[-1..-1] == ')'
679     sql << "CHECK #{check}"
680   when :primary_key
681     sql << "#{primary_key_constraint_sql_fragment(constraint)} #{literal(constraint[:columns])}"
682   when :foreign_key
683     sql << column_references_table_constraint_sql(constraint.merge(:deferrable=>nil))
684   when :unique
685     sql << "#{unique_constraint_sql_fragment(constraint)} #{literal(constraint[:columns])}"
686   else
687     raise Error, "Invalid constraint type #{constraint[:type]}, should be :check, :primary_key, :foreign_key, or :unique"
688   end
689   constraint_deferrable_sql_append(sql, constraint[:deferrable])
690   sql
691 end
create_table_as(name, sql, options) click to toggle source

Run SQL statement to create the table with the given name from the given SELECT sql statement.

    # File lib/sequel/database/schema_methods.rb
765 def create_table_as(name, sql, options)
766   sql = sql.sql if sql.is_a?(Sequel::Dataset)
767   run(create_table_as_sql(name, sql, options))
768 end
create_table_as_sql(name, sql, options) click to toggle source

SQL statement for creating a table from the result of a SELECT statement. sql should be a string representing a SELECT query.

    # File lib/sequel/database/schema_methods.rb
772 def create_table_as_sql(name, sql, options)
773   "#{create_table_prefix_sql(name, options)} AS #{sql}"
774 end
create_table_from_generator(name, generator, options) click to toggle source

Execute the create table statements using the generator.

    # File lib/sequel/database/schema_methods.rb
707 def create_table_from_generator(name, generator, options)
708   execute_ddl(create_table_sql(name, generator, options))
709 end
create_table_generator_class() click to toggle source

The class used for create_table generators.

    # File lib/sequel/database/schema_methods.rb
712 def create_table_generator_class
713   Schema::CreateTableGenerator
714 end
create_table_indexes_from_generator(name, generator, options) click to toggle source

Execute the create index statements using the generator.

    # File lib/sequel/database/schema_methods.rb
717 def create_table_indexes_from_generator(name, generator, options)
718   e = options[:ignore_index_errors] || options[:if_not_exists]
719   generator.indexes.each do |index|
720     begin
721       transaction(:savepoint=>:only, :skip_transaction=>supports_transactional_ddl? == false) do
722         index_sql_list(name, [index]).each{|sql| execute_ddl(sql)}
723       end
724     rescue Error
725       raise unless e
726     end
727   end
728 end
create_table_prefix_sql(name, options) click to toggle source

SQL fragment for initial part of CREATE TABLE statement

    # File lib/sequel/database/schema_methods.rb
777 def create_table_prefix_sql(name, options)
778   "CREATE #{temporary_table_sql if options[:temp]}TABLE#{' IF NOT EXISTS' if options[:if_not_exists]} #{create_table_table_name_sql(name, options)}"
779 end
create_table_sql(name, generator, options) click to toggle source

SQL statement for creating a table with the given name, columns, and options

    # File lib/sequel/database/schema_methods.rb
731 def create_table_sql(name, generator, options)
732   unless supports_named_column_constraints?
733     # Split column constraints into table constraints if they have a name
734     generator.columns.each do |c|
735       if (constraint_name = c.delete(:foreign_key_constraint_name)) && (table = c.delete(:table))
736         opts = {}
737         opts[:name] = constraint_name
738         [:key, :on_delete, :on_update, :deferrable].each{|k| opts[k] = c[k]}
739         generator.foreign_key([c[:name]], table, opts)
740       end
741       if (constraint_name = c.delete(:unique_constraint_name)) && c.delete(:unique)
742         generator.unique(c[:name], :name=>constraint_name)
743       end
744       if (constraint_name = c.delete(:primary_key_constraint_name)) && c.delete(:primary_key)
745         generator.primary_key([c[:name]], :name=>constraint_name)
746       end
747     end
748   end
749 
750   unless can_add_primary_key_constraint_on_nullable_columns?
751     if pk = generator.constraints.find{|op| op[:type] == :primary_key}
752       pk[:columns].each do |column|
753         if matched_column = generator.columns.find{|gc| gc[:name] == column}
754           matched_column[:null] = false
755         end
756       end
757     end
758   end
759 
760   "#{create_table_prefix_sql(name, options)} (#{column_list_sql(generator)})"
761 end
create_table_table_name_sql(name, options) click to toggle source

The SQL to use for a table name when creating a table. Use of the :temp option can result in different SQL, because the rules for temp table naming can differ between databases, and temp tables should not use the default_schema.

    # File lib/sequel/database/schema_methods.rb
786 def create_table_table_name_sql(name, options)
787   options[:temp] ? create_table_temp_table_name_sql(name, options) : quote_schema_table(name)
788 end
create_table_temp_table_name_sql(name, _options) click to toggle source

The SQL to use for the table name for a temporary table.

    # File lib/sequel/database/schema_methods.rb
791 def create_table_temp_table_name_sql(name, _options)
792   name.is_a?(String) ? quote_identifier(name) : literal(name)
793 end
create_view_prefix_sql(name, options) click to toggle source

SQL fragment for initial part of CREATE VIEW statement

    # File lib/sequel/database/schema_methods.rb
796 def create_view_prefix_sql(name, options)
797   create_view_sql_append_columns("CREATE #{'OR REPLACE 'if options[:replace]}VIEW #{quote_schema_table(name)}", options[:columns])
798 end
create_view_sql(name, source, options) click to toggle source

SQL statement for creating a view.

    # File lib/sequel/database/schema_methods.rb
801 def create_view_sql(name, source, options)
802   source = source.sql if source.is_a?(Dataset)
803   sql = String.new
804   sql << "#{create_view_prefix_sql(name, options)} AS #{source}"
805   if check = options[:check]
806     sql << " WITH#{' LOCAL' if check == :local} CHECK OPTION"
807   end
808   sql
809 end
create_view_sql_append_columns(sql, columns) click to toggle source

Append the column list to the SQL, if a column list is given.

    # File lib/sequel/database/schema_methods.rb
812 def create_view_sql_append_columns(sql, columns)
813   if columns
814     sql += ' ('
815     schema_utility_dataset.send(:identifier_list_append, sql, columns)
816     sql << ')'
817   end
818   sql
819 end
default_index_name(table_name, columns) click to toggle source

Default index name for the table and columns, may be too long for certain databases.

    # File lib/sequel/database/schema_methods.rb
823 def default_index_name(table_name, columns)
824   schema, table = schema_and_table(table_name)
825   "#{"#{schema}_" if schema}#{table}_#{columns.map{|c| [String, Symbol].any?{|cl| c.is_a?(cl)} ? c : literal(c).gsub(/\W/, '_')}.join('_')}_index"
826 end
drop_index_sql(table, op) click to toggle source

The SQL to drop an index for the table.

    # File lib/sequel/database/schema_methods.rb
836 def drop_index_sql(table, op)
837   "DROP INDEX #{quote_identifier(op[:name] || default_index_name(table, op[:columns]))}"
838 end
drop_table_sql(name, options) click to toggle source

SQL DDL statement to drop the table with the given name.

    # File lib/sequel/database/schema_methods.rb
841 def drop_table_sql(name, options)
842   "DROP TABLE#{' IF EXISTS' if options[:if_exists]} #{quote_schema_table(name)}#{' CASCADE' if options[:cascade]}"
843 end
drop_view_sql(name, options) click to toggle source

SQL DDL statement to drop a view with the given name.

    # File lib/sequel/database/schema_methods.rb
846 def drop_view_sql(name, options)
847   "DROP VIEW#{' IF EXISTS' if options[:if_exists]} #{quote_schema_table(name)}#{' CASCADE' if options[:cascade]}"
848 end
filter_expr(arg=nil, &block) click to toggle source

Proxy the filter_expr call to the dataset, used for creating constraints. Support passing Proc arguments as blocks, as well as treating plain strings as literal strings, so that previous migrations that used this API do not break.

    # File lib/sequel/database/schema_methods.rb
853 def filter_expr(arg=nil, &block)
854   if arg.is_a?(Proc) && !block
855     block = arg
856     arg = nil
857   elsif arg.is_a?(String)
858     arg = Sequel.lit(arg)
859   elsif arg.is_a?(Array)
860     if arg.first.is_a?(String)
861       arg = Sequel.lit(*arg)
862     elsif arg.length > 1
863       arg = Sequel.&(*arg)
864     end
865   end
866   schema_utility_dataset.literal(schema_utility_dataset.send(:filter_expr, arg, &block))
867 end
foreign_key_name(table_name, columns) click to toggle source

Get foreign key name for given table and columns.

    # File lib/sequel/database/schema_methods.rb
829 def foreign_key_name(table_name, columns)
830   keys = foreign_key_list(table_name).select{|key| key[:columns] == columns}
831   raise(Error, "#{keys.empty? ? 'Missing' : 'Ambiguous'} foreign key for #{columns.inspect}") unless keys.size == 1
832   keys.first[:name]
833 end
index_definition_sql(table_name, index) click to toggle source

SQL statement for creating an index for the table with the given name and index specifications.

    # File lib/sequel/database/schema_methods.rb
871 def index_definition_sql(table_name, index)
872   index_name = index[:name] || default_index_name(table_name, index[:columns])
873   raise Error, "Index types are not supported for this database" if index[:type]
874   raise Error, "Partial indexes are not supported for this database" if index[:where] && !supports_partial_indexes?
875   "CREATE #{'UNIQUE ' if index[:unique]}INDEX #{quote_identifier(index_name)} ON #{quote_schema_table(table_name)} #{literal(index[:columns])}#{" WHERE #{filter_expr(index[:where])}" if index[:where]}"
876 end
index_sql_list(table_name, indexes) click to toggle source

Array of SQL statements, one for each index specification, for the given table.

    # File lib/sequel/database/schema_methods.rb
880 def index_sql_list(table_name, indexes)
881   indexes.map{|i| index_definition_sql(table_name, i)}
882 end
join_table_name(hash, options) click to toggle source

Extract the join table name from the arguments given to create_join_table. Also does argument validation for the create_join_table method.

    # File lib/sequel/database/schema_methods.rb
886 def join_table_name(hash, options)
887   entries = hash.values
888   raise Error, "must have 2 entries in hash given to (create|drop)_join_table" unless entries.length == 2
889   if options[:name]
890     options[:name]
891   else
892     table_names = entries.map{|e| join_table_name_extract(e)}
893     table_names.map(&:to_s).sort.join('_')
894   end
895 end
join_table_name_extract(entry) click to toggle source

Extract an individual join table name, which should either be a string or symbol, or a hash containing one of those as the value for :table.

    # File lib/sequel/database/schema_methods.rb
899 def join_table_name_extract(entry)
900   case entry
901   when Symbol, String
902     entry
903   when Hash
904     join_table_name_extract(entry[:table])
905   else
906     raise Error, "can't extract table name from #{entry.inspect}"
907   end
908 end
on_delete_clause(action) click to toggle source

SQL fragment to use for ON DELETE, based on the given action. The following actions are recognized:

:cascade

Delete rows referencing this row.

:no_action

Raise an error if other rows reference this row, allow deferring of the integrity check. This is the default.

:restrict

Raise an error if other rows reference this row, but do not allow deferring the integrity check.

:set_default

Set columns referencing this row to their default value.

:set_null

Set columns referencing this row to NULL.

Any other object given is just converted to a string, with “_” converted to “ ” and upcased.

    # File lib/sequel/database/schema_methods.rb
923 def on_delete_clause(action)
924   action.to_s.tr("_", " ").upcase
925 end
on_update_clause(action) click to toggle source

Alias of on_delete_clause, since the two usually behave the same.

    # File lib/sequel/database/schema_methods.rb
928 def on_update_clause(action)
929   on_delete_clause(action)
930 end
primary_key_constraint_sql_fragment(_) click to toggle source

Add fragment for primary key specification, separated for easier overridding.

    # File lib/sequel/database/schema_methods.rb
933 def primary_key_constraint_sql_fragment(_)
934   'PRIMARY KEY'
935 end
quote_schema_table(table) click to toggle source

Proxy the quote_schema_table method to the dataset

    # File lib/sequel/database/schema_methods.rb
938 def quote_schema_table(table)
939   schema_utility_dataset.quote_schema_table(table)
940 end
rename_table_sql(name, new_name) click to toggle source

SQL statement for renaming a table.

    # File lib/sequel/database/schema_methods.rb
943 def rename_table_sql(name, new_name)
944   "ALTER TABLE #{quote_schema_table(name)} RENAME TO #{quote_schema_table(new_name)}"
945 end
schema_and_table(table_name) click to toggle source

Split the schema information from the table

    # File lib/sequel/database/schema_methods.rb
948 def schema_and_table(table_name)
949   schema_utility_dataset.schema_and_table(table_name)
950 end
schema_autoincrementing_primary_key?(schema) click to toggle source

Return true if the given column schema represents an autoincrementing primary key.

    # File lib/sequel/database/schema_methods.rb
953 def schema_autoincrementing_primary_key?(schema)
954   !!(schema[:primary_key] && schema[:auto_increment])
955 end
schema_utility_dataset() click to toggle source

The dataset to use for proxying certain schema methods.

    # File lib/sequel/database/schema_methods.rb
958 def schema_utility_dataset
959   @default_dataset
960 end
split_qualifiers(table_name) click to toggle source

Split the schema information from the table

    # File lib/sequel/database/schema_methods.rb
963 def split_qualifiers(table_name)
964   schema_utility_dataset.split_qualifiers(table_name)
965 end
temporary_table_sql() click to toggle source

SQL fragment for temporary table

    # File lib/sequel/database/schema_methods.rb
968 def temporary_table_sql
969   'TEMPORARY '
970 end
type_literal(column) click to toggle source

SQL fragment specifying the type of a given column.

    # File lib/sequel/database/schema_methods.rb
973 def type_literal(column)
974   case column[:type]
975   when Class
976     type_literal_generic(column)
977   when :Bignum
978     type_literal_generic_bignum_symbol(column)
979   else
980     type_literal_specific(column)
981   end
982 end
type_literal_generic(column) click to toggle source

SQL fragment specifying the full type of a column, consider the type with possible modifiers.

    # File lib/sequel/database/schema_methods.rb
986 def type_literal_generic(column)
987   meth = "type_literal_generic_#{column[:type].name.to_s.downcase}"
988   if respond_to?(meth, true)
989     # Allow calling private methods as per type literal generic methods are private
990     send(meth, column)
991   else
992     raise Error, "Unsupported ruby class used as database type: #{column[:type]}"
993   end
994 end
type_literal_generic_bigdecimal(column) click to toggle source

Alias for type_literal_generic_numeric, to make overriding in a subclass easier.

    # File lib/sequel/database/schema_methods.rb
997 def type_literal_generic_bigdecimal(column)
998   type_literal_generic_numeric(column)
999 end
type_literal_generic_bignum_symbol(column) click to toggle source

Sequel uses the bigint type by default for :Bignum symbol.

     # File lib/sequel/database/schema_methods.rb
1002 def type_literal_generic_bignum_symbol(column)
1003   :bigint
1004 end
type_literal_generic_date(column) click to toggle source

Sequel uses the date type by default for Dates.

     # File lib/sequel/database/schema_methods.rb
1007 def type_literal_generic_date(column)
1008   :date
1009 end
type_literal_generic_datetime(column) click to toggle source

Sequel uses the timestamp type by default for DateTimes.

     # File lib/sequel/database/schema_methods.rb
1012 def type_literal_generic_datetime(column)
1013   :timestamp
1014 end
type_literal_generic_falseclass(column) click to toggle source

Alias for type_literal_generic_trueclass, to make overriding in a subclass easier.

     # File lib/sequel/database/schema_methods.rb
1017 def type_literal_generic_falseclass(column)
1018   type_literal_generic_trueclass(column)
1019 end
type_literal_generic_file(column) click to toggle source

Sequel uses the blob type by default for Files.

     # File lib/sequel/database/schema_methods.rb
1022 def type_literal_generic_file(column)
1023   :blob
1024 end
type_literal_generic_fixnum(column) click to toggle source

Alias for type_literal_generic_integer, to make overriding in a subclass easier.

     # File lib/sequel/database/schema_methods.rb
1027 def type_literal_generic_fixnum(column)
1028   type_literal_generic_integer(column)
1029 end
type_literal_generic_float(column) click to toggle source

Sequel uses the double precision type by default for Floats.

     # File lib/sequel/database/schema_methods.rb
1032 def type_literal_generic_float(column)
1033   :"double precision"
1034 end
type_literal_generic_integer(column) click to toggle source

Sequel uses the integer type by default for integers

     # File lib/sequel/database/schema_methods.rb
1037 def type_literal_generic_integer(column)
1038   :integer
1039 end
type_literal_generic_numeric(column) click to toggle source

Sequel uses the numeric type by default for Numerics and BigDecimals. If a size is given, it is used, otherwise, it will default to whatever the database default is for an unsized value.

     # File lib/sequel/database/schema_methods.rb
1044 def type_literal_generic_numeric(column)
1045   column[:size] ? "numeric(#{Array(column[:size]).join(', ')})" : :numeric
1046 end
type_literal_generic_only_time(column) click to toggle source

Use time by default for Time values if :only_time option is used.

     # File lib/sequel/database/schema_methods.rb
1073 def type_literal_generic_only_time(column)
1074   :time
1075 end
type_literal_generic_string(column) click to toggle source

Sequel uses the varchar type by default for Strings. If a size isn’t present, Sequel assumes a size of 255. If the :fixed option is used, Sequel uses the char type. If the :text option is used, Sequel uses the :text type.

     # File lib/sequel/database/schema_methods.rb
1052 def type_literal_generic_string(column)
1053   if column[:text]
1054     uses_clob_for_text? ? :clob : :text
1055   elsif column[:fixed]
1056     "char(#{column[:size]||default_string_column_size})"
1057   else
1058     "varchar(#{column[:size]||default_string_column_size})"
1059   end
1060 end
type_literal_generic_time(column) click to toggle source

Sequel uses the timestamp type by default for Time values. If the :only_time option is used, the time type is used.

     # File lib/sequel/database/schema_methods.rb
1064 def type_literal_generic_time(column)
1065   if column[:only_time]
1066     type_literal_generic_only_time(column)
1067   else
1068     type_literal_generic_datetime(column)
1069   end
1070 end
type_literal_generic_trueclass(column) click to toggle source

Sequel uses the boolean type by default for TrueClass and FalseClass.

     # File lib/sequel/database/schema_methods.rb
1078 def type_literal_generic_trueclass(column)
1079   :boolean
1080 end
type_literal_specific(column) click to toggle source

SQL fragment for the given type of a column if the column is not one of the generic types specified with a ruby class.

     # File lib/sequel/database/schema_methods.rb
1084 def type_literal_specific(column)
1085   type = column[:type]
1086   type = "double precision" if type.to_s == 'double'
1087   column[:size] ||= default_string_column_size if type.to_s == 'varchar'
1088   elements = column[:size] || column[:elements]
1089   "#{type}#{literal(Array(elements)) if elements}#{' UNSIGNED' if column[:unsigned]}"
1090 end
unique_constraint_sql_fragment(_) click to toggle source

Add fragment for unique specification, separated for easier overridding.

     # File lib/sequel/database/schema_methods.rb
1093 def unique_constraint_sql_fragment(_)
1094   'UNIQUE'
1095 end
uses_clob_for_text?() click to toggle source

Whether clob should be used for String text: true columns.

     # File lib/sequel/database/schema_methods.rb
1098 def uses_clob_for_text?
1099   false
1100 end

3 - Methods that create datasets

↑ top

Public Instance Methods

[](*args) click to toggle source

Returns a dataset for the database. If the first argument is a string, the method acts as an alias for Database#fetch, returning a dataset for arbitrary SQL, with or without placeholders:

DB['SELECT * FROM items'].all
DB['SELECT * FROM items WHERE name = ?', my_name].all

Otherwise, acts as an alias for Database#from, setting the primary table for the dataset:

DB[:items].sql #=> "SELECT * FROM items"
   # File lib/sequel/database/dataset.rb
21 def [](*args)
22   args.first.is_a?(String) ? fetch(*args) : from(*args)
23 end
dataset() click to toggle source

Returns a blank dataset for this database.

DB.dataset # SELECT *
DB.dataset.from(:items) # SELECT * FROM items
   # File lib/sequel/database/dataset.rb
29 def dataset
30   @dataset_class.new(self)
31 end
fetch(sql, *args, &block) click to toggle source

Returns a dataset instance for the given SQL string:

ds = DB.fetch('SELECT * FROM items')

You can then call methods on the dataset to retrieve results:

ds.all
# SELECT * FROM items
# => [{:column=>value, ...}, ...]

If a block is given, it is passed to each on the resulting dataset to iterate over the records returned by the query:

DB.fetch('SELECT * FROM items'){|r| p r}
# {:column=>value, ...}
# ...

fetch can also perform parameterized queries for protection against SQL injection:

ds = DB.fetch('SELECT * FROM items WHERE name = ?', "my name")
ds.all
# SELECT * FROM items WHERE name = 'my name'

See caveats listed in Dataset#with_sql regarding datasets using custom SQL and the methods that can be called on them.

   # File lib/sequel/database/dataset.rb
59 def fetch(sql, *args, &block)
60   ds = @default_dataset.with_sql(sql, *args)
61   ds.each(&block) if block
62   ds
63 end
from(*args, &block) click to toggle source

Returns a new dataset with the from method invoked. If a block is given, it acts as a virtual row block

DB.from(:items) # SELECT * FROM items
DB.from{schema[:table]} # SELECT * FROM schema.table
   # File lib/sequel/database/dataset.rb
70 def from(*args, &block)
71   if block
72     @default_dataset.from(*args, &block)
73   elsif args.length == 1 && (table = args[0]).is_a?(Symbol)
74     @default_dataset.send(:cached_dataset, :"_from_#{table}_ds"){@default_dataset.from(table)}
75   else
76     @default_dataset.from(*args)
77   end
78 end
select(*args, &block) click to toggle source

Returns a new dataset with the select method invoked.

DB.select(1) # SELECT 1
DB.select{server_version.function} # SELECT server_version()
DB.select(:id).from(:items) # SELECT id FROM items
   # File lib/sequel/database/dataset.rb
85 def select(*args, &block)
86   @default_dataset.select(*args, &block)
87 end

4 - Methods relating to adapters, connecting, disconnecting, and sharding

↑ top

Constants

ADAPTERS

Array of supported database adapters

Attributes

pool[R]

The connection pool for this Database instance. All Database instances have their own connection pools.

Public Class Methods

adapter_class(scheme) click to toggle source

The Database subclass for the given adapter scheme. Raises Sequel::AdapterNotFound if the adapter could not be loaded.

   # File lib/sequel/database/connecting.rb
16 def self.adapter_class(scheme)
17   scheme.is_a?(Class) ? scheme : load_adapter(scheme.to_sym)
18 end
adapter_scheme() click to toggle source

Returns the scheme symbol for the Database class.

   # File lib/sequel/database/connecting.rb
21 def self.adapter_scheme
22   @scheme
23 end
connect(conn_string, opts = OPTS) { || ... } click to toggle source

Connects to a database. See Sequel.connect.

   # File lib/sequel/database/connecting.rb
26 def self.connect(conn_string, opts = OPTS)
27   case conn_string
28   when String
29     if conn_string.start_with?('jdbc:')
30       c = adapter_class(:jdbc)
31       opts = opts.merge(:orig_opts=>opts.dup)
32       opts = {:uri=>conn_string}.merge!(opts)
33     else
34       uri = URI.parse(conn_string)
35       scheme = uri.scheme
36       c = adapter_class(scheme)
37       opts = c.send(:options_from_uri, uri).merge!(opts).merge!(:orig_opts=>opts.dup, :uri=>conn_string, :adapter=>scheme)
38     end
39   when Hash
40     opts = conn_string.merge(opts)
41     opts = opts.merge(:orig_opts=>opts.dup)
42     c = adapter_class(opts[:adapter_class] || opts[:adapter] || opts['adapter'])
43   else
44     raise Error, "Sequel::Database.connect takes either a Hash or a String, given: #{conn_string.inspect}"
45   end
46 
47   opts = opts.inject({}) do |m, (k,v)|
48     k = :user if k.to_s == 'username'
49     m[k.to_sym] = v
50     m
51   end
52 
53   begin
54     db = c.new(opts)
55     if defined?(yield)
56       return yield(db)
57     end
58   ensure
59     if defined?(yield)
60       db.disconnect if db
61       Sequel.synchronize{::Sequel::DATABASES.delete(db)}
62     end
63   end
64   db
65 end
load_adapter(scheme, opts=OPTS) click to toggle source

Load the adapter from the file system. Raises Sequel::AdapterNotFound if the adapter cannot be loaded, or if the adapter isn’t registered correctly after being loaded. Options:

:map

The Hash in which to look for an already loaded adapter (defaults to ADAPTER_MAP).

:subdir

The subdirectory of sequel/adapters to look in, only to be used for loading subadapters.

   # File lib/sequel/database/connecting.rb
73 def self.load_adapter(scheme, opts=OPTS)
74   map = opts[:map] || ADAPTER_MAP
75   if subdir = opts[:subdir]
76     file = "#{subdir}/#{scheme}"
77   else
78     file = scheme
79   end
80   
81   unless obj = Sequel.synchronize{map[scheme]}
82     # attempt to load the adapter file
83     begin
84       require "sequel/adapters/#{file}"
85     rescue LoadError => e
86       # If subadapter file doesn't exist, just return,
87       # using the main adapter class without database customizations.
88       return if subdir
89       raise Sequel.convert_exception_class(e, AdapterNotFound)
90     end
91     
92     # make sure we actually loaded the adapter
93     unless obj = Sequel.synchronize{map[scheme]}
94       raise AdapterNotFound, "Could not load #{file} adapter: adapter class not registered in ADAPTER_MAP"
95     end
96   end
97 
98   obj
99 end
set_shared_adapter_scheme(scheme, mod) click to toggle source

Sets the given module as the shared adapter module for the given scheme. Used to register shared adapters for use by the mock adapter. Example:

# in file sequel/adapters/shared/mydb.rb
module Sequel::MyDB
  Sequel::Database.set_shared_adapter_scheme :mydb, self

  def self.mock_adapter_setup(db)
    # ...
  end

  module DatabaseMethods
    # ...
  end

  module DatasetMethods
    # ...
  end
end

would allow the mock adapter to return a Database instance that supports the MyDB syntax via:

Sequel.connect('mock://mydb')
    # File lib/sequel/database/connecting.rb
143 def self.set_shared_adapter_scheme(scheme, mod)
144   Sequel.synchronize{SHARED_ADAPTER_MAP[scheme] = mod}
145 end

Public Instance Methods

adapter_scheme() click to toggle source

Returns the scheme symbol for this instance’s class, which reflects which adapter is being used. In some cases, this can be the same as the database_type (for native adapters), in others (i.e. adapters with subadapters), it will be different.

Sequel.connect('jdbc:postgres://...').adapter_scheme
# => :jdbc
    # File lib/sequel/database/connecting.rb
158 def adapter_scheme
159   self.class.adapter_scheme
160 end
add_servers(servers) click to toggle source

Dynamically add new servers or modify server options at runtime. Also adds new servers to the connection pool. Only usable when using a sharded connection pool.

servers argument should be a hash with server name symbol keys and hash or proc values. If a servers key is already in use, it’s value is overridden with the value provided.

DB.add_servers(f: {host: "hash_host_f"})
    # File lib/sequel/database/connecting.rb
170 def add_servers(servers)
171   unless sharded?
172     raise Error, "cannot call Database#add_servers on a Database instance that does not use a sharded connection pool"
173   end
174 
175   h = @opts[:servers]
176   Sequel.synchronize{h.merge!(servers)}
177   @pool.add_servers(servers.keys)
178 end
database_type() click to toggle source

The database type for this database object, the same as the adapter scheme by default. Should be overridden in adapters (especially shared adapters) to be the correct type, so that even if two separate Database objects are using different adapters you can tell that they are using the same database type. Even better, you can tell that two Database objects that are using the same adapter are connecting to different database types.

Sequel.connect('jdbc:postgres://...').database_type
# => :postgres
    # File lib/sequel/database/connecting.rb
189 def database_type
190   adapter_scheme
191 end
disconnect(opts = OPTS) click to toggle source

Disconnects all available connections from the connection pool. Any connections currently in use will not be disconnected. Options:

:server

Should be a symbol specifing the server to disconnect from,

or an array of symbols to specify multiple servers.

Example:

DB.disconnect # All servers
DB.disconnect(server: :server1) # Single server
DB.disconnect(server: [:server1, :server2]) # Multiple servers
    # File lib/sequel/database/connecting.rb
203 def disconnect(opts = OPTS)
204   pool.disconnect(opts)
205 end
disconnect_connection(conn) click to toggle source

Should only be called by the connection pool code to disconnect a connection. By default, calls the close method on the connection object, since most adapters use that, but should be overwritten on other adapters.

    # File lib/sequel/database/connecting.rb
210 def disconnect_connection(conn)
211   conn.close
212 end
new_connection(server) click to toggle source

Connect to the given server/shard. Handles database-generic post-connection setup not handled by connect, using the :after_connect and :connect_sqls options.

    # File lib/sequel/database/connecting.rb
244 def new_connection(server)
245   conn = connect(server)
246   opts = server_opts(server)
247 
248   if ac = opts[:after_connect]
249     if ac.arity == 2
250       ac.call(conn, server)
251     else
252       ac.call(conn)
253     end
254   end
255 
256   if cs = opts[:connect_sqls]
257     cs.each do |sql|
258       log_connection_execute(conn, sql)
259     end
260   end
261 
262   conn
263 end
remove_servers(*servers) click to toggle source

Dynamically remove existing servers from the connection pool. Only usable when using a sharded connection pool

servers should be symbols or arrays of symbols. If a nonexistent server is specified, it is ignored. If no servers have been specified for this database, no changes are made. If you attempt to remove the :default server, an error will be raised.

DB.remove_servers(:f1, :f2)
    # File lib/sequel/database/connecting.rb
223 def remove_servers(*servers)
224   unless sharded?
225     raise Error, "cannot call Database#remove_servers on a Database instance that does not use a sharded connection pool"
226   end
227 
228   h = @opts[:servers]
229   servers.flatten.each{|s| Sequel.synchronize{h.delete(s)}}
230   @pool.remove_servers(servers)
231 end
servers() click to toggle source

An array of servers/shards for this Database object.

DB.servers # Unsharded: => [:default]
DB.servers # Sharded:   => [:default, :server1, :server2]
    # File lib/sequel/database/connecting.rb
237 def servers
238   pool.servers
239 end
single_threaded?() click to toggle source

Returns true if the database is using a single-threaded connection pool.

    # File lib/sequel/database/connecting.rb
266 def single_threaded?
267   @single_threaded
268 end
synchronize(server=nil, &block) click to toggle source

Acquires a database connection, yielding it to the passed block. This is useful if you want to make sure the same connection is used for all database queries in the block. It is also useful if you want to gain direct access to the underlying connection object if you need to do something Sequel does not natively support.

If a server option is given, acquires a connection for that specific server, instead of the :default server.

DB.synchronize do |conn|
  # ...
end
    # File lib/sequel/database/connecting.rb
282 def synchronize(server=nil, &block)
283   @pool.hold(server || :default, &block)
284 end
test_connection(server=nil) click to toggle source

Attempts to acquire a database connection. Returns true if successful. Will probably raise an Error if unsuccessful. If a server argument is given, attempts to acquire a database connection to the given server/shard.

    # File lib/sequel/database/connecting.rb
290 def test_connection(server=nil)
291   synchronize(server){|conn|}
292   true
293 end
valid_connection?(conn) click to toggle source

Check whether the given connection is currently valid, by running a query against it. If the query fails, the connection should probably be removed from the connection pool.

    # File lib/sequel/database/connecting.rb
299 def valid_connection?(conn)
300   sql = valid_connection_sql
301   begin
302     log_connection_execute(conn, sql)
303   rescue Sequel::DatabaseError, *database_error_classes
304     false
305   else
306     true
307   end
308 end

Private Instance Methods

connection_pool_default_options() click to toggle source

The default options for the connection pool.

    # File lib/sequel/database/connecting.rb
313 def connection_pool_default_options
314   {}
315 end
server_opts(server) click to toggle source

Return the options for the given server by merging the generic options for all server with the specific options for the given server specified in the :servers option.

    # File lib/sequel/database/connecting.rb
320 def server_opts(server)
321   opts = if @opts[:servers] and server_options = @opts[:servers][server]
322     case server_options
323     when Hash
324       @opts.merge(server_options)
325     when Proc
326       @opts.merge(server_options.call(self))
327     else
328       raise Error, 'Server opts should be a hash or proc'
329     end
330   elsif server.is_a?(Hash)
331     @opts.merge(server)
332   else
333     @opts.dup
334   end
335 
336   if pr = opts[:connect_opts_proc]
337     pr.call(opts)
338   end
339 
340   opts.delete(:servers)
341   opts
342 end
valid_connection_sql() click to toggle source

The SQL query to issue to check if a connection is valid.

    # File lib/sequel/database/connecting.rb
345 def valid_connection_sql
346   @valid_connection_sql ||= select(nil).sql
347 end

5 - Methods that set defaults for created datasets

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Attributes

dataset_class[R]

The class to use for creating datasets. Should respond to new with the Database argument as the first argument, and an optional options hash.

Public Instance Methods

dataset_class=(c) click to toggle source

If the database has any dataset modules associated with it, use a subclass of the given class that includes the modules as the dataset class.

   # File lib/sequel/database/dataset_defaults.rb
18 def dataset_class=(c)
19   unless @dataset_modules.empty?
20     c = Class.new(c)
21     @dataset_modules.each{|m| c.send(:include, m)}
22   end
23   @dataset_class = c
24   reset_default_dataset
25 end
extend_datasets(mod=nil, &block) click to toggle source

Equivalent to extending all datasets produced by the database with a module. What it actually does is use a subclass of the current dataset_class as the new dataset_class, and include the module in the subclass. Instead of a module, you can provide a block that is used to create an anonymous module.

This allows you to override any of the dataset methods even if they are defined directly on the dataset class that this Database object uses.

If a block is given, a Dataset::DatasetModule instance is created, allowing for the easy creation of named dataset methods that will do caching.

Examples:

# Introspect columns for all of DB's datasets
DB.extend_datasets(Sequel::ColumnsIntrospection)

# Trace all SELECT queries by printing the SQL and the full backtrace
DB.extend_datasets do
  def fetch_rows(sql)
    puts sql
    puts caller
    super
  end
end

# Add some named dataset methods
DB.extend_datasets do
  order :by_id, :id
  select :with_id_and_name, :id, :name
  where :active, :active
end

DB[:table].active.with_id_and_name.by_id
# SELECT id, name FROM table WHERE active ORDER BY id
   # File lib/sequel/database/dataset_defaults.rb
62 def extend_datasets(mod=nil, &block)
63   raise(Error, "must provide either mod or block, not both") if mod && block
64   mod = Dataset::DatasetModule.new(&block) if block
65   if @dataset_modules.empty?
66    @dataset_modules = [mod]
67    @dataset_class = Class.new(@dataset_class)
68   else
69    @dataset_modules << mod
70   end
71   @dataset_class.send(:include, mod)
72   reset_default_dataset
73 end

Private Instance Methods

dataset_class_default() click to toggle source

The default dataset class to use for the database

   # File lib/sequel/database/dataset_defaults.rb
78 def dataset_class_default
79   Sequel::Dataset
80 end
quote_identifiers_default() click to toggle source

Whether to quote identifiers by default for this database, true by default.

   # File lib/sequel/database/dataset_defaults.rb
89 def quote_identifiers_default
90   true
91 end
reset_default_dataset() click to toggle source

Reset the default dataset used by most Database methods that create datasets.

   # File lib/sequel/database/dataset_defaults.rb
83 def reset_default_dataset
84   Sequel.synchronize{@symbol_literal_cache.clear}
85   @default_dataset = dataset
86 end

6 - Methods relating to logging

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Attributes

log_connection_info[RW]

Whether to include information about the connection in use when logging queries.

log_warn_duration[RW]

Numeric specifying the duration beyond which queries are logged at warn level instead of info level.

loggers[RW]

Array of SQL loggers to use for this database.

sql_log_level[RW]

Log level at which to log SQL queries. This is actually the method sent to the logger, so it should be the method name symbol. The default is :info, it can be set to :debug to log at DEBUG level.

Public Instance Methods

log_connection_yield(sql, conn, args=nil) { || ... } click to toggle source

Yield to the block, logging any errors at error level to all loggers, and all other queries with the duration at warn or info level.

   # File lib/sequel/database/logging.rb
37 def log_connection_yield(sql, conn, args=nil)
38   return yield if skip_logging?
39   sql = "#{connection_info(conn) if conn && log_connection_info}#{sql}#{"; #{args.inspect}" if args}"
40   timer = Sequel.start_timer
41 
42   begin
43     yield
44   rescue => e
45     log_exception(e, sql)
46     raise
47   ensure
48     log_duration(Sequel.elapsed_seconds_since(timer), sql) unless e
49   end
50 end
log_exception(exception, message) click to toggle source

Log a message at error level, with information about the exception.

   # File lib/sequel/database/logging.rb
26 def log_exception(exception, message)
27   log_each(:error, "#{exception.class}: #{exception.message.strip if exception.message}: #{message}")
28 end
log_info(message, args=nil) click to toggle source

Log a message at level info to all loggers.

   # File lib/sequel/database/logging.rb
31 def log_info(message, args=nil)
32   log_each(:info, args ? "#{message}; #{args.inspect}" : message)
33 end
logger=(logger) click to toggle source

Remove any existing loggers and just use the given logger:

DB.logger = Logger.new($stdout)
   # File lib/sequel/database/logging.rb
55 def logger=(logger)
56   @loggers = Array(logger)
57 end

Private Instance Methods

connection_info(conn) click to toggle source

String including information about the connection, for use when logging connection info.

   # File lib/sequel/database/logging.rb
69 def connection_info(conn)
70   "(conn: #{conn.__id__}) "
71 end
log_connection_execute(conn, sql) click to toggle source

Log the given SQL and then execute it on the connection, used by the transaction code.

   # File lib/sequel/database/logging.rb
75 def log_connection_execute(conn, sql)
76   log_connection_yield(sql, conn){conn.public_send(connection_execute_method, sql)}
77 end
log_duration(duration, message) click to toggle source

Log message with message prefixed by duration at info level, or warn level if duration is greater than log_warn_duration.

   # File lib/sequel/database/logging.rb
81 def log_duration(duration, message)
82   log_each((lwd = log_warn_duration and duration >= lwd) ? :warn : sql_log_level, "(#{sprintf('%0.6fs', duration)}) #{message}")
83 end
log_each(level, message) click to toggle source

Log message at level (which should be :error, :warn, or :info) to all loggers.

   # File lib/sequel/database/logging.rb
87 def log_each(level, message)
88   @loggers.each{|logger| logger.public_send(level, message)}
89 end
skip_logging?() click to toggle source

Determine if logging should be skipped. Defaults to true if no loggers have been specified.

   # File lib/sequel/database/logging.rb
63 def skip_logging?
64   @loggers.empty?
65 end

7 - Miscellaneous methods

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Constants

CHECK_CONSTRAINT_SQLSTATES
DEFAULT_DATABASE_ERROR_REGEXPS

Empty exception regexp to class map, used by default if Sequel doesn’t have specific support for the database in use.

DEFAULT_STRING_COLUMN_SIZE

The general default size for string columns for all Sequel::Database instances.

EXTENSIONS

Hash of extension name symbols to callable objects to load the extension into the Database object (usually by extending it with a module defined in the extension).

FOREIGN_KEY_CONSTRAINT_SQLSTATES
NOT_NULL_CONSTRAINT_SQLSTATES
SCHEMA_TYPE_CLASSES

Mapping of schema type symbols to class or arrays of classes for that symbol.

SERIALIZATION_CONSTRAINT_SQLSTATES
UNIQUE_CONSTRAINT_SQLSTATES

Attributes

check_string_typecast_bytesize[RW]

Whether to check the bytesize of strings before typecasting (to avoid typecasting strings that would be too long for the given type), true by default. Strings that are too long will raise a typecasting error.

default_string_column_size[RW]

The specific default size of string columns for this Sequel::Database, usually 255 by default.

opts[R]

The options hash for this database

timezone[W]

Set the timezone to use for this database, overridding Sequel.database_timezone.

Public Class Methods

after_initialize(&block) click to toggle source

Register a hook that will be run when a new Database is instantiated. It is called with the new database handle.

   # File lib/sequel/database/misc.rb
34 def self.after_initialize(&block)
35   raise Error, "must provide block to after_initialize" unless block
36   Sequel.synchronize do
37     previous = @initialize_hook
38     @initialize_hook = proc do |db|
39       previous.call(db)
40       block.call(db)
41     end
42   end
43 end
extension(*extensions) click to toggle source

Apply an extension to all Database objects created in the future.

   # File lib/sequel/database/misc.rb
46 def self.extension(*extensions)
47   after_initialize{|db| db.extension(*extensions)}
48 end
new(opts = OPTS) click to toggle source

Constructs a new instance of a database connection with the specified options hash.

Accepts the following options:

:after_connect

A callable object called after each new connection is made, with the connection object (and server argument if the callable accepts 2 arguments), useful for customizations that you want to apply to all connections.

:before_preconnect

Callable that runs after extensions from :preconnect_extensions are loaded, but before any connections are created.

:cache_schema

Whether schema should be cached for this Database instance

:check_string_typecast_bytesize

Whether to check the bytesize of strings before typecasting.

:connect_sqls

An array of sql strings to execute on each new connection, after :after_connect runs.

:connect_opts_proc

Callable object for modifying options hash used when connecting, designed for cases where the option values (e.g. password) are automatically rotated on a regular basis without involvement from the application using Sequel.

:default_string_column_size

The default size of string columns, 255 by default.

:extensions

Extensions to load into this Database instance. Can be a symbol, array of symbols, or string with extensions separated by columns. These extensions are loaded after connections are made by the :preconnect option.

:keep_reference

Whether to keep a reference to this instance in Sequel::DATABASES, true by default.

:logger

A specific logger to use.

:loggers

An array of loggers to use.

:log_connection_info

Whether connection information should be logged when logging queries.

:log_warn_duration

The number of elapsed seconds after which queries should be logged at warn level.

:name

A name to use for the Database object, displayed in PoolTimeout.

:preconnect

Automatically create the maximum number of connections, so that they don’t need to be created as needed. This is useful when connecting takes a long time and you want to avoid possible latency during runtime. Set to :concurrently to create the connections in separate threads. Otherwise they’ll be created sequentially.

:preconnect_extensions

Similar to the :extensions option, but loads the extensions before the connections are made by the :preconnect option.

:quote_identifiers

Whether to quote identifiers.

:servers

A hash specifying a server/shard specific options, keyed by shard symbol.

:single_threaded

Whether to use a single-threaded connection pool.

:sql_log_level

Method to use to log SQL to a logger, :info by default.

For sharded connection pools, :after_connect and :connect_sqls can be specified per-shard.

All options given are also passed to the connection pool. Additional options respected by the connection pool are :max_connections, :pool_timeout, :servers, and :servers_hash. See the connection pool documentation for details.

    # File lib/sequel/database/misc.rb
149 def initialize(opts = OPTS)
150   @opts ||= opts
151   @opts = connection_pool_default_options.merge(@opts)
152   @loggers = Array(@opts[:logger]) + Array(@opts[:loggers])
153   @opts[:servers] = {} if @opts[:servers].is_a?(String)
154   @sharded = !!@opts[:servers]
155   @opts[:adapter_class] = self.class
156   @opts[:single_threaded] = @single_threaded = typecast_value_boolean(@opts.fetch(:single_threaded, Sequel.single_threaded))
157   @default_string_column_size = @opts[:default_string_column_size] || DEFAULT_STRING_COLUMN_SIZE
158   @check_string_typecast_bytesize = typecast_value_boolean(@opts.fetch(:check_string_typecast_bytesize, true))
159 
160   @schemas = {}
161   @prepared_statements = {}
162   @transactions = {}
163   @transactions.compare_by_identity
164   @symbol_literal_cache = {}
165 
166   @timezone = nil
167 
168   @dataset_class = dataset_class_default
169   @cache_schema = typecast_value_boolean(@opts.fetch(:cache_schema, true))
170   @dataset_modules = []
171   @loaded_extensions = []
172   @schema_type_classes = SCHEMA_TYPE_CLASSES.dup
173 
174   self.sql_log_level = @opts[:sql_log_level] ? @opts[:sql_log_level].to_sym : :info
175   self.log_warn_duration = @opts[:log_warn_duration]
176   self.log_connection_info = typecast_value_boolean(@opts[:log_connection_info])
177 
178   @pool = ConnectionPool.get_pool(self, @opts)
179 
180   reset_default_dataset
181   adapter_initialize
182 
183   keep_reference = typecast_value_boolean(@opts[:keep_reference]) != false
184   begin
185     Sequel.synchronize{::Sequel::DATABASES.push(self)} if keep_reference
186     Sequel::Database.run_after_initialize(self)
187 
188     initialize_load_extensions(:preconnect_extensions)
189 
190     if before_preconnect = @opts[:before_preconnect]
191       before_preconnect.call(self)
192     end
193 
194     if typecast_value_boolean(@opts[:preconnect]) && @pool.respond_to?(:preconnect, true)
195       concurrent = typecast_value_string(@opts[:preconnect]) == "concurrently"
196       @pool.send(:preconnect, concurrent)
197     end
198 
199     initialize_load_extensions(:extensions)
200     test_connection if typecast_value_boolean(@opts.fetch(:test, true)) && respond_to?(:connect, true)
201   rescue
202     Sequel.synchronize{::Sequel::DATABASES.delete(self)} if keep_reference
203     raise
204   end
205 end
register_extension(ext, mod=nil, &block) click to toggle source

Register an extension callback for Database objects. ext should be the extension name symbol, and mod should either be a Module that the database is extended with, or a callable object called with the database object. If mod is not provided, a block can be provided and is treated as the mod object.

   # File lib/sequel/database/misc.rb
55 def self.register_extension(ext, mod=nil, &block)
56   if mod
57     raise(Error, "cannot provide both mod and block to Database.register_extension") if block
58     if mod.is_a?(Module)
59       block = proc{|db| db.extend(mod)}
60     else
61       block = mod
62     end
63   end
64   Sequel.synchronize{EXTENSIONS[ext] = block}
65 end
run_after_initialize(instance) click to toggle source

Run the after_initialize hook for the given instance.

   # File lib/sequel/database/misc.rb
68 def self.run_after_initialize(instance)
69   @initialize_hook.call(instance)
70 end

Private Class Methods

options_from_uri(uri) click to toggle source
   # File lib/sequel/database/misc.rb
85 def self.options_from_uri(uri)
86   uri_options = uri_to_options(uri)
87   uri.query.split('&').map{|s| s.split('=')}.each{|k,v| uri_options[k.to_sym] = v if k && !k.empty?} unless uri.query.to_s.strip.empty?
88   uri_options.to_a.each{|k,v| uri_options[k] = URI::DEFAULT_PARSER.unescape(v) if v.is_a?(String)}
89   uri_options
90 end
uri_to_options(uri) click to toggle source

Converts a uri to an options hash. These options are then passed to a newly created database object.

   # File lib/sequel/database/misc.rb
74 def self.uri_to_options(uri)
75   {
76     :user => uri.user,
77     :password => uri.password,
78     :port => uri.port,
79     :host => uri.hostname,
80     :database => (m = /\/(.*)/.match(uri.path)) && (m[1])
81   }
82 end

Public Instance Methods

cast_type_literal(type) click to toggle source

Cast the given type to a literal type

DB.cast_type_literal(Float) # double precision
DB.cast_type_literal(:foo)  # foo
    # File lib/sequel/database/misc.rb
234 def cast_type_literal(type)
235   type_literal(:type=>type)
236 end
extension(*exts) click to toggle source

Load an extension into the receiver. In addition to requiring the extension file, this also modifies the database to work with the extension (usually extending it with a module defined in the extension file). If no related extension file exists or the extension does not have specific support for Database objects, an Error will be raised. Returns self.

    # File lib/sequel/database/misc.rb
243 def extension(*exts)
244   Sequel.extension(*exts)
245   exts.each do |ext|
246     if pr = Sequel.synchronize{EXTENSIONS[ext]}
247       if Sequel.synchronize{@loaded_extensions.include?(ext) ? false : (@loaded_extensions << ext)}
248         pr.call(self)
249       end
250     else
251       raise(Error, "Extension #{ext} does not have specific support handling individual databases (try: Sequel.extension #{ext.inspect})")
252     end
253   end
254   self
255 end
freeze() click to toggle source

Freeze internal data structures for the Database instance.

Calls superclass method
    # File lib/sequel/database/misc.rb
208 def freeze
209   valid_connection_sql
210   metadata_dataset
211   @opts.freeze
212   @loggers.freeze
213   @pool.freeze
214   @dataset_class.freeze
215   @dataset_modules.freeze
216   @schema_type_classes.freeze
217   @loaded_extensions.freeze
218   metadata_dataset
219   super
220 end
from_application_timestamp(v) click to toggle source

Convert the given timestamp from the application’s timezone, to the databases’s timezone or the default database timezone if the database does not have a timezone.

    # File lib/sequel/database/misc.rb
260 def from_application_timestamp(v)
261   Sequel.convert_output_timestamp(v, timezone)
262 end
inspect() click to toggle source

Returns a string representation of the Database object, including the database type, host, database, and user, if present.

    # File lib/sequel/database/misc.rb
266 def inspect
267   s = String.new
268   s << "#<#{self.class}"
269   s << " database_type=#{database_type}" if database_type && database_type != adapter_scheme
270 
271   keys = [:host, :database, :user]
272   opts = self.opts
273   if !keys.any?{|k| opts[k]} && opts[:uri]
274     opts = self.class.send(:options_from_uri, URI.parse(opts[:uri]))
275   end
276 
277   keys.each do |key|
278     val = opts[key]
279     if val && val != ''
280       s << " #{key}=#{val}"
281     end
282   end
283 
284   s << ">"
285 end
literal(v) click to toggle source

Proxy the literal call to the dataset.

DB.literal(1)   # 1
DB.literal(:a)  # "a" # or `a`, [a], or a, depending on identifier quoting
DB.literal("a") # 'a'
    # File lib/sequel/database/misc.rb
292 def literal(v)
293   schema_utility_dataset.literal(v)
294 end
literal_symbol(sym) click to toggle source

Return the literalized version of the symbol if cached, or nil if it is not cached.

    # File lib/sequel/database/misc.rb
298 def literal_symbol(sym)
299   Sequel.synchronize{@symbol_literal_cache[sym]}
300 end
literal_symbol_set(sym, lit) click to toggle source

Set the cached value of the literal symbol.

    # File lib/sequel/database/misc.rb
303 def literal_symbol_set(sym, lit)
304   Sequel.synchronize{@symbol_literal_cache[sym] = lit}
305 end
prepared_statement(name) click to toggle source

Synchronize access to the prepared statements cache.

    # File lib/sequel/database/misc.rb
308 def prepared_statement(name)
309   Sequel.synchronize{prepared_statements[name]}
310 end
quote_identifier(v) click to toggle source

Proxy the quote_identifier method to the dataset, useful for quoting unqualified identifiers for use outside of datasets.

    # File lib/sequel/database/misc.rb
315 def quote_identifier(v)
316   schema_utility_dataset.quote_identifier(v)
317 end
schema_type_class(type) click to toggle source

Return ruby class or array of classes for the given type symbol.

    # File lib/sequel/database/misc.rb
320 def schema_type_class(type)
321   @schema_type_classes[type]
322 end
serial_primary_key_options() click to toggle source

Default serial primary key options, used by the table creation code.

    # File lib/sequel/database/misc.rb
325 def serial_primary_key_options
326   {:primary_key => true, :type => Integer, :auto_increment => true}
327 end
set_prepared_statement(name, ps) click to toggle source

Cache the prepared statement object at the given name.

    # File lib/sequel/database/misc.rb
330 def set_prepared_statement(name, ps)
331   Sequel.synchronize{prepared_statements[name] = ps}
332 end
sharded?() click to toggle source

Whether this database instance uses multiple servers, either for sharding or for primary/replica configurations.

    # File lib/sequel/database/misc.rb
336 def sharded?
337   @sharded
338 end
timezone() click to toggle source

The timezone to use for this database, defaulting to Sequel.database_timezone.

    # File lib/sequel/database/misc.rb
341 def timezone
342   @timezone || Sequel.database_timezone
343 end
to_application_timestamp(v) click to toggle source

Convert the given timestamp to the application’s timezone, from the databases’s timezone or the default database timezone if the database does not have a timezone.

    # File lib/sequel/database/misc.rb
348 def to_application_timestamp(v)
349   Sequel.convert_timestamp(v, timezone)
350 end
typecast_value(column_type, value) click to toggle source

Typecast the value to the given column_type. Calls typecast_value_#{column_type} if the method exists, otherwise returns the value. This method should raise Sequel::InvalidValue if assigned value is invalid.

    # File lib/sequel/database/misc.rb
357 def typecast_value(column_type, value)
358   return nil if value.nil?
359   meth = "typecast_value_#{column_type}"
360   begin
361     # Allow calling private methods as per-type typecasting methods are private
362     respond_to?(meth, true) ? send(meth, value) : value
363   rescue ArgumentError, TypeError => e
364     raise Sequel.convert_exception_class(e, InvalidValue)
365   end
366 end
uri() click to toggle source

Returns the URI use to connect to the database. If a URI was not used when connecting, returns nil.

    # File lib/sequel/database/misc.rb
370 def uri
371   opts[:uri]
372 end
url() click to toggle source

Explicit alias of uri for easier subclassing.

    # File lib/sequel/database/misc.rb
375 def url
376   uri
377 end

Private Instance Methods

_typecast_value_string_to_decimal(value) click to toggle source

:nocov:

    # File lib/sequel/database/misc.rb
571 def _typecast_value_string_to_decimal(value)
572   d = BigDecimal(value)
573   if d.zero?
574     # BigDecimal parsing is loose by default, returning a 0 value for
575     # invalid input.  If a zero value is received, use Float to check
576     # for validity.
577     begin
578       Float(value)
579     rescue ArgumentError
580       raise InvalidValue, "invalid value for BigDecimal: #{value.inspect}"
581     end
582   end
583   d
584 end
adapter_initialize() click to toggle source

Per adapter initialization method, empty by default.

    # File lib/sequel/database/misc.rb
382 def adapter_initialize
383 end
blank_object?(obj) click to toggle source

Returns true when the object is considered blank. The only objects that are blank are nil, false, strings with all whitespace, and ones that respond true to empty?

    # File lib/sequel/database/misc.rb
389 def blank_object?(obj)
390   return obj.blank? if obj.respond_to?(:blank?)
391   case obj
392   when NilClass, FalseClass
393     true
394   when Numeric, TrueClass
395     false
396   when String
397     obj.strip.empty?
398   else
399     obj.respond_to?(:empty?) ? obj.empty? : false
400   end
401 end
database_error_class(exception, opts) click to toggle source

Return the Sequel::DatabaseError subclass to wrap the given exception in.

    # File lib/sequel/database/misc.rb
412 def database_error_class(exception, opts)
413   database_specific_error_class(exception, opts) || DatabaseError
414 end
database_error_regexps() click to toggle source

An enumerable yielding pairs of regexps and exception classes, used to match against underlying driver exception messages in order to raise a more specific Sequel::DatabaseError subclass.

    # File lib/sequel/database/misc.rb
406 def database_error_regexps
407   DEFAULT_DATABASE_ERROR_REGEXPS
408 end
database_exception_sqlstate(exception, opts) click to toggle source

Return the SQLState for the given exception, if one can be determined

    # File lib/sequel/database/misc.rb
417 def database_exception_sqlstate(exception, opts)
418   nil
419 end
database_specific_error_class(exception, opts) click to toggle source

Return a specific Sequel::DatabaseError exception class if one is appropriate for the underlying exception, or nil if there is no specific exception class.

    # File lib/sequel/database/misc.rb
424 def database_specific_error_class(exception, opts)
425   return DatabaseDisconnectError if disconnect_error?(exception, opts)
426 
427   if sqlstate = database_exception_sqlstate(exception, opts)
428     if klass = database_specific_error_class_from_sqlstate(sqlstate)
429       return klass
430     end
431   else
432     database_error_regexps.each do |regexp, klss|
433       return klss if exception.message =~ regexp
434     end
435   end
436 
437   nil
438 end
database_specific_error_class_from_sqlstate(sqlstate) click to toggle source

Given the SQLState, return the appropriate DatabaseError subclass.

    # File lib/sequel/database/misc.rb
446 def database_specific_error_class_from_sqlstate(sqlstate)
447   case sqlstate
448   when *NOT_NULL_CONSTRAINT_SQLSTATES
449     NotNullConstraintViolation
450   when *FOREIGN_KEY_CONSTRAINT_SQLSTATES
451     ForeignKeyConstraintViolation
452   when *UNIQUE_CONSTRAINT_SQLSTATES
453     UniqueConstraintViolation
454   when *CHECK_CONSTRAINT_SQLSTATES
455     CheckConstraintViolation
456   when *SERIALIZATION_CONSTRAINT_SQLSTATES
457     SerializationFailure
458   end
459 end
disconnect_error?(exception, opts) click to toggle source

Return true if exception represents a disconnect error, false otherwise.

    # File lib/sequel/database/misc.rb
462 def disconnect_error?(exception, opts)
463   opts[:disconnect]
464 end
initialize_load_extensions(key) click to toggle source

Load extensions during initialization from the given key in opts.

    # File lib/sequel/database/misc.rb
467 def initialize_load_extensions(key)
468   case exts = @opts[key]
469   when String
470     extension(*exts.split(',').map(&:to_sym))
471   when Array
472     extension(*exts)
473   when Symbol
474     extension(exts)
475   when nil
476     # nothing
477   else
478     raise Error, "unsupported Database #{key.inspect} option: #{@opts[key].inspect}"
479   end
480 end
raise_error(exception, opts=OPTS) click to toggle source

Convert the given exception to an appropriate Sequel::DatabaseError subclass, keeping message and backtrace.

    # File lib/sequel/database/misc.rb
484 def raise_error(exception, opts=OPTS)
485   if !opts[:classes] || Array(opts[:classes]).any?{|c| exception.is_a?(c)}
486     raise Sequel.convert_exception_class(exception, database_error_class(exception, opts))
487   else
488     raise exception
489   end
490 end
swallow_database_error() { || ... } click to toggle source

Swallow database errors, unless they are connect/disconnect errors.

    # File lib/sequel/database/misc.rb
493 def swallow_database_error
494   yield
495 rescue Sequel::DatabaseDisconnectError, DatabaseConnectionError
496   # Always raise disconnect errors
497   raise
498 rescue Sequel::DatabaseError
499   # Don't raise other database errors.
500   nil
501 # else
502 #   Don't rescue other exceptions, they will be raised normally.
503 end
typecast_check_length(value, max_size) click to toggle source

Check the bytesize of the string value, if value is a string.

    # File lib/sequel/database/misc.rb
515 def typecast_check_length(value, max_size)
516   typecast_check_string_length(value, max_size) if String === value
517   value
518 end
typecast_check_string_length(string, max_size) click to toggle source

Check the bytesize of a string before conversion. There is no point trying to typecast strings that would be way too long.

    # File lib/sequel/database/misc.rb
507 def typecast_check_string_length(string, max_size)
508   if @check_string_typecast_bytesize && string.bytesize > max_size
509     raise InvalidValue, "string too long to typecast (bytesize: #{string.bytesize}, max: #{max_size})"
510   end
511   string
512 end
typecast_value_blob(value) click to toggle source

Typecast the value to an SQL::Blob

    # File lib/sequel/database/misc.rb
521 def typecast_value_blob(value)
522   value.is_a?(Sequel::SQL::Blob) ? value : Sequel::SQL::Blob.new(value)
523 end
typecast_value_boolean(value) click to toggle source

Typecast the value to true, false, or nil

    # File lib/sequel/database/misc.rb
526 def typecast_value_boolean(value)
527   case value
528   when false, 0, "0", /\Af(alse)?\z/i, /\Ano?\z/i
529     false
530   else
531     blank_object?(value) ? nil : true
532   end
533 end
typecast_value_date(value) click to toggle source

Typecast the value to a Date

    # File lib/sequel/database/misc.rb
536 def typecast_value_date(value)
537   case value
538   when DateTime, Time
539     Date.new(value.year, value.month, value.day)
540   when Date
541     value
542   when String
543     Sequel.string_to_date(typecast_check_string_length(value, 100))
544   when Hash
545     Date.new(*[:year, :month, :day].map{|x| typecast_check_length(value[x] || value[x.to_s], 100).to_i})
546   else
547     raise InvalidValue, "invalid value for Date: #{value.inspect}"
548   end
549 end
typecast_value_datetime(value) click to toggle source

Typecast the value to a DateTime or Time depending on Sequel.datetime_class

    # File lib/sequel/database/misc.rb
552 def typecast_value_datetime(value)
553   case value
554   when String
555     Sequel.typecast_to_application_timestamp(typecast_check_string_length(value, 100))
556   when Hash
557     [:year, :month, :day, :hour, :minute, :second, :nanos, :offset].each do |x|
558       typecast_check_length(value[x] || value[x.to_s], 100)
559     end
560     Sequel.typecast_to_application_timestamp(value)
561   else
562     Sequel.typecast_to_application_timestamp(value)
563   end
564 end
typecast_value_decimal(value) click to toggle source

Typecast the value to a BigDecimal

    # File lib/sequel/database/misc.rb
589 def typecast_value_decimal(value)
590   case value
591   when BigDecimal
592     value
593   when Numeric
594     BigDecimal(value.to_s)
595   when String
596     _typecast_value_string_to_decimal(typecast_check_string_length(value, 1000))
597   else
598     raise InvalidValue, "invalid value for BigDecimal: #{value.inspect}"
599   end
600 end
typecast_value_float(value) click to toggle source

Typecast the value to a Float

    # File lib/sequel/database/misc.rb
603 def typecast_value_float(value)
604   Float(typecast_check_length(value, 1000))
605 end
typecast_value_integer(value) click to toggle source

Typecast the value to an Integer

    # File lib/sequel/database/misc.rb
608 def typecast_value_integer(value)
609   case value
610   when String
611     typecast_check_string_length(value, 100)
612     if value =~ /\A-?0+(\d)/
613       Integer(value, 10)
614     else
615       Integer(value)
616     end
617   else
618     Integer(value)
619   end
620 end
typecast_value_string(value) click to toggle source

Typecast the value to a String

    # File lib/sequel/database/misc.rb
623 def typecast_value_string(value)
624   case value
625   when Hash, Array
626     raise Sequel::InvalidValue, "invalid value for String: #{value.inspect}"
627   else
628     value.to_s
629   end
630 end
typecast_value_time(value) click to toggle source

Typecast the value to a Time

    # File lib/sequel/database/misc.rb
633 def typecast_value_time(value)
634   case value
635   when Time
636     if value.is_a?(SQLTime)
637       value
638     else
639       SQLTime.create(value.hour, value.min, value.sec, value.nsec/1000.0)
640     end
641   when String
642     Sequel.string_to_time(typecast_check_string_length(value, 100))
643   when Hash
644     SQLTime.create(*[:hour, :minute, :second].map{|x| typecast_check_length(value[x] || value[x.to_s], 100).to_i})
645   else
646     raise Sequel::InvalidValue, "invalid value for Time: #{value.inspect}"
647   end
648 end

8 - Methods related to database transactions

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Constants

TRANSACTION_ISOLATION_LEVELS

Attributes

transaction_isolation_level[RW]

The default transaction isolation level for this database, used for all future transactions. For MSSQL, this should be set to something if you ever plan to use the :isolation option to Database#transaction, as on MSSQL if affects all future transactions on the same connection.

Public Instance Methods

after_commit(opts=OPTS) { || ... } click to toggle source

If a transaction is not currently in process, yield to the block immediately. Otherwise, add the block to the list of blocks to call after the currently in progress transaction commits (and only if it commits). Options:

:savepoint

If currently inside a savepoint, only run this hook on transaction commit if all enclosing savepoints have been released.

:server

The server/shard to use.

   # File lib/sequel/database/transactions.rb
31 def after_commit(opts=OPTS, &block)
32   raise Error, "must provide block to after_commit" unless block
33   synchronize(opts[:server]) do |conn|
34     if h = _trans(conn)
35       raise Error, "cannot call after_commit in a prepared transaction" if h[:prepare]
36       if opts[:savepoint] && in_savepoint?(conn)
37         add_savepoint_hook(conn, :after_commit, block)
38       else
39         add_transaction_hook(conn, :after_commit, block)
40       end
41     else
42       yield
43     end
44   end
45 end
after_rollback(opts=OPTS, &block) click to toggle source

If a transaction is not currently in progress, ignore the block. Otherwise, add the block to the list of the blocks to call after the currently in progress transaction rolls back (and only if it rolls back). Options:

:savepoint

If currently inside a savepoint, run this hook immediately when any enclosing savepoint is rolled back, which may be before the transaction commits or rollsback.

:server

The server/shard to use.

   # File lib/sequel/database/transactions.rb
55 def after_rollback(opts=OPTS, &block)
56   raise Error, "must provide block to after_rollback" unless block
57   synchronize(opts[:server]) do |conn|
58     if h = _trans(conn)
59       raise Error, "cannot call after_rollback in a prepared transaction" if h[:prepare]
60       if opts[:savepoint] && in_savepoint?(conn)
61         add_savepoint_hook(conn, :after_rollback, block)
62       else
63         add_transaction_hook(conn, :after_rollback, block)
64       end
65     end
66   end
67 end
in_transaction?(opts=OPTS) click to toggle source

Return true if already in a transaction given the options, false otherwise. Respects the :server option for selecting a shard.

    # File lib/sequel/database/transactions.rb
113 def in_transaction?(opts=OPTS)
114   synchronize(opts[:server]){|conn| !!_trans(conn)}
115 end
rollback_checker(opts=OPTS) click to toggle source

Returns a proc that you can call to check if the transaction has been rolled back. The proc will return nil if the transaction is still in progress, true if the transaction was rolled back, and false if it was committed. Raises an Error if called outside a transaction. Respects the :server option for selecting a shard.

    # File lib/sequel/database/transactions.rb
123 def rollback_checker(opts=OPTS)
124   synchronize(opts[:server]) do |conn|
125     raise Error, "not in a transaction" unless t = _trans(conn)
126     t[:rollback_checker] ||= proc{Sequel.synchronize{t[:rolled_back]}}
127   end
128 end
rollback_on_exit(opts=OPTS) click to toggle source

When exiting the transaction block through methods other than an exception (e.g. normal exit, non-local return, or throw), set the current transaction to rollback instead of committing. This is designed for use in cases where you want to preform a non-local return but also want to rollback instead of committing. Options:

:cancel

Cancel the current rollback_on_exit setting, so exiting will commit instead of rolling back.

:savepoint

Rollback only the current savepoint if inside a savepoint. Can also be an positive integer value to rollback that number of enclosing savepoints, up to and including the transaction itself. If the database does not support savepoints, this option is ignored and the entire transaction is affected.

:server

The server/shard the transaction is being executed on.

    # File lib/sequel/database/transactions.rb
 83 def rollback_on_exit(opts=OPTS)
 84   synchronize(opts[:server]) do |conn|
 85     raise Error, "Cannot call Sequel:: Database#rollback_on_exit unless inside a transaction" unless h = _trans(conn)
 86     rollback = !opts[:cancel]
 87 
 88     if supports_savepoints?
 89       savepoints = h[:savepoints]
 90 
 91       if level = opts[:savepoint]
 92         level = 1 if level == true
 93         raise Error, "invalid :savepoint option to Database#rollback_on_exit: #{level.inspect}" unless level.is_a?(Integer)
 94         raise Error, "cannot pass nonpositive integer (#{level.inspect}) as :savepoint option to Database#rollback_on_exit" if level < 1
 95         level.times do |i|
 96           break unless savepoint = savepoints[-1 - i]
 97           savepoint[:rollback_on_exit] = rollback
 98         end
 99       else
100         savepoints[0][:rollback_on_exit] = rollback
101       end
102     else
103       h[:rollback_on_exit] = rollback
104     end
105   end
106 
107   nil
108 end
transaction(opts=OPTS) { |conn| ... } click to toggle source

Starts a database transaction. When a database transaction is used, either all statements are successful or none of the statements are successful. Note that MySQL MyISAM tables do not support transactions.

The following general options are respected:

:auto_savepoint

Automatically use a savepoint for Database#transaction calls inside this transaction block.

:isolation

The transaction isolation level to use for this transaction, should be :uncommitted, :committed, :repeatable, or :serializable, used if given and the database/adapter supports customizable transaction isolation levels.

:num_retries

The number of times to retry if the :retry_on option is used. The default is 5 times. Can be set to nil to retry indefinitely, but that is not recommended.

:before_retry

Proc to execute before retrying if the :retry_on option is used. Called with two arguments: the number of retry attempts (counting the current one) and the error the last attempt failed with.

:prepare

A string to use as the transaction identifier for a prepared transaction (two-phase commit), if the database/adapter supports prepared transactions.

:retry_on

An exception class or array of exception classes for which to automatically retry the transaction. Can only be set if not inside an existing transaction. Note that this should not be used unless the entire transaction block is idempotent, as otherwise it can cause non-idempotent behavior to execute multiple times.

:rollback

Can be set to :reraise to reraise any Sequel::Rollback exceptions raised, or :always to always rollback even if no exceptions occur (useful for testing).

:server

The server to use for the transaction. Set to :default, :read_only, or whatever symbol you used in the connect string when naming your servers.

:savepoint

Whether to create a new savepoint for this transaction, only respected if the database/adapter supports savepoints. By default Sequel will reuse an existing transaction, so if you want to use a savepoint you must use this option. If the surrounding transaction uses :auto_savepoint, you can set this to false to not use a savepoint. If the value given for this option is :only, it will only create a savepoint if it is inside a transaction.

:skip_transaction

If set, do not actually open a transaction or savepoint, just checkout a connection and yield it.

PostgreSQL specific options:

:deferrable

(9.1+) If present, set to DEFERRABLE if true or NOT DEFERRABLE if false.

:read_only

If present, set to READ ONLY if true or READ WRITE if false.

:synchronous

if non-nil, set synchronous_commit appropriately. Valid values true, :on, false, :off, :local (9.1+), and :remote_write (9.2+).

    # File lib/sequel/database/transactions.rb
179 def transaction(opts=OPTS, &block)
180   opts = Hash[opts]
181   if retry_on = opts[:retry_on]
182     tot_retries = opts.fetch(:num_retries, 5)
183     num_retries = 0
184     begin
185       opts[:retry_on] = nil
186       opts[:retrying] = true
187       transaction(opts, &block)
188     rescue *retry_on => e
189       num_retries += 1
190       if tot_retries.nil? || num_retries <= tot_retries
191         opts[:before_retry].call(num_retries, e) if opts[:before_retry]
192         retry
193       end
194       raise
195     end
196   else
197     synchronize(opts[:server]) do |conn|
198       if opts[:skip_transaction]
199         return yield(conn)
200       end
201 
202       if opts[:savepoint] == :only
203         if supports_savepoints?
204           if _trans(conn)
205             opts[:savepoint] = true
206           else
207             return yield(conn)
208           end
209         else
210           opts[:savepoint] = false
211         end
212       end
213 
214       if opts[:savepoint] && !supports_savepoints?
215         raise Sequel::InvalidOperation, "savepoints not supported on #{database_type}"
216       end
217 
218       if already_in_transaction?(conn, opts)
219         if opts[:rollback] == :always && !opts.has_key?(:savepoint)
220           if supports_savepoints? 
221             opts[:savepoint] = true
222           else
223             raise Sequel::Error, "cannot set :rollback=>:always transaction option if already inside a transaction"
224           end
225         end
226 
227         if opts[:savepoint] != false && (stack = _trans(conn)[:savepoints]) && stack.last[:auto_savepoint]
228           opts[:savepoint] = true
229         end
230 
231         unless opts[:savepoint]
232           if opts[:retrying]
233             raise Sequel::Error, "cannot set :retry_on options if you are already inside a transaction"
234           end
235           return yield(conn)
236         end
237       end
238 
239       _transaction(conn, opts, &block)
240     end
241   end
242 end

Private Instance Methods

_trans(conn) click to toggle source

Synchronize access to the current transactions, returning the hash of options for the current transaction (if any)

    # File lib/sequel/database/transactions.rb
295 def _trans(conn)
296   Sequel.synchronize{@transactions[conn]}
297 end
_transaction(conn, opts=OPTS) { |conn| ... } click to toggle source

Internal generic transaction method. Any exception raised by the given block will cause the transaction to be rolled back. If the exception is not a Sequel::Rollback, the error will be reraised. If no exception occurs inside the block, the transaction is commited.

    # File lib/sequel/database/transactions.rb
250 def _transaction(conn, opts=OPTS)
251   rollback = opts[:rollback]
252   begin
253     add_transaction(conn, opts)
254     begin_transaction(conn, opts)
255     if rollback == :always
256       begin
257         ret = yield(conn)
258       rescue Exception => e1
259         raise e1
260       ensure
261         raise ::Sequel::Rollback unless e1
262       end
263     else
264       yield(conn)
265     end
266   rescue Exception => e
267     begin
268       rollback_transaction(conn, opts)
269     rescue Exception => e3
270     end
271     transaction_error(e, :conn=>conn, :rollback=>rollback)
272     raise e3 if e3
273     ret
274   ensure
275     begin
276       committed = commit_or_rollback_transaction(e, conn, opts)
277     rescue Exception => e2
278       begin
279         raise_error(e2, :classes=>database_error_classes, :conn=>conn)
280       rescue Sequel::DatabaseError => e4
281         begin
282           rollback_transaction(conn, opts)
283         ensure
284           raise e4
285         end
286       end
287     ensure
288       remove_transaction(conn, committed)
289     end
290   end
291 end
add_savepoint_hook(conn, type, block) click to toggle source

Set the given callable as a hook to be called. Type should be either :after_commit or :after_rollback.

    # File lib/sequel/database/transactions.rb
322 def add_savepoint_hook(conn, type, block)
323   savepoint = _trans(conn)[:savepoints].last
324   (savepoint[type] ||= []) << block
325 end
add_transaction(conn, opts) click to toggle source

Add the current thread to the list of active transactions

    # File lib/sequel/database/transactions.rb
300 def add_transaction(conn, opts)
301   hash = transaction_options(conn, opts)
302 
303   if supports_savepoints?
304     if t = _trans(conn)
305       t[:savepoints].push({:auto_savepoint=>opts[:auto_savepoint]})
306       return
307     else
308       hash[:savepoints] = [{:auto_savepoint=>opts[:auto_savepoint]}]
309       if (prep = opts[:prepare]) && supports_prepared_transactions?
310         hash[:prepare] = prep
311       end
312     end
313   elsif (prep = opts[:prepare]) && supports_prepared_transactions?
314     hash[:prepare] = prep
315   end
316 
317   Sequel.synchronize{@transactions[conn] = hash}
318 end
add_transaction_hook(conn, type, block) click to toggle source

Set the given callable as a hook to be called. Type should be either :after_commit or :after_rollback.

    # File lib/sequel/database/transactions.rb
329 def add_transaction_hook(conn, type, block)
330   hooks = _trans(conn)[type] ||= []
331   hooks << block
332 end
already_in_transaction?(conn, opts) click to toggle source

Whether the given connection is already inside a transaction

    # File lib/sequel/database/transactions.rb
335 def already_in_transaction?(conn, opts)
336   _trans(conn) && (!supports_savepoints? || !opts[:savepoint])
337 end
begin_new_transaction(conn, opts) click to toggle source

Start a new database transaction on the given connection

    # File lib/sequel/database/transactions.rb
356 def begin_new_transaction(conn, opts)
357   log_connection_execute(conn, begin_transaction_sql)
358   set_transaction_isolation(conn, opts)
359 end
begin_savepoint(conn, opts) click to toggle source

Issue query to begin a new savepoint.

    # File lib/sequel/database/transactions.rb
346 def begin_savepoint(conn, opts)
347   log_connection_execute(conn, begin_savepoint_sql(savepoint_level(conn)-1))
348 end
begin_savepoint_sql(depth) click to toggle source

SQL to start a new savepoint

    # File lib/sequel/database/transactions.rb
351 def begin_savepoint_sql(depth)
352   "SAVEPOINT autopoint_#{depth}"
353 end
begin_transaction(conn, opts=OPTS) click to toggle source

Start a new database transaction or a new savepoint on the given connection.

    # File lib/sequel/database/transactions.rb
362 def begin_transaction(conn, opts=OPTS)
363   if in_savepoint?(conn)
364     begin_savepoint(conn, opts)
365   else
366     begin_new_transaction(conn, opts)
367   end
368 end
begin_transaction_sql() click to toggle source

SQL to BEGIN a transaction.

    # File lib/sequel/database/transactions.rb
371 def begin_transaction_sql
372   'BEGIN'
373 end
commit_or_rollback_transaction(exception, conn, opts) click to toggle source

Whether to commit the current transaction. Thread.current.status is checked because Thread#kill skips rescue blocks (so exception would be nil), but the transaction should still be rolled back. On Ruby 1.9 (but not 2.0+), the thread status will still be “run”, so Thread#kill will erroneously commit the transaction, and there isn’t a workaround.

    # File lib/sequel/database/transactions.rb
380 def commit_or_rollback_transaction(exception, conn, opts)
381   if exception
382     false
383   else
384     if rollback_on_transaction_exit?(conn, opts)
385       rollback_transaction(conn, opts)
386       false
387     else
388       commit_transaction(conn, opts)
389       true
390     end
391   end
392 end
commit_savepoint_sql(depth) click to toggle source

SQL to commit a savepoint

    # File lib/sequel/database/transactions.rb
395 def commit_savepoint_sql(depth)
396   "RELEASE SAVEPOINT autopoint_#{depth}"
397 end
commit_transaction(conn, opts=OPTS) click to toggle source

Commit the active transaction on the connection

    # File lib/sequel/database/transactions.rb
400 def commit_transaction(conn, opts=OPTS)
401   if supports_savepoints?
402     depth = savepoint_level(conn)
403     log_connection_execute(conn, depth > 1 ? commit_savepoint_sql(depth-1) : commit_transaction_sql)
404   else
405     log_connection_execute(conn, commit_transaction_sql)
406   end
407 end
commit_transaction_sql() click to toggle source

SQL to COMMIT a transaction.

    # File lib/sequel/database/transactions.rb
410 def commit_transaction_sql
411   'COMMIT'
412 end
connection_execute_method() click to toggle source

Method called on the connection object to execute SQL on the database, used by the transaction code.

    # File lib/sequel/database/transactions.rb
416 def connection_execute_method
417   :execute
418 end
database_error_classes() click to toggle source

Which transaction errors to translate, blank by default.

    # File lib/sequel/database/transactions.rb
421 def database_error_classes
422   []
423 end
in_savepoint?(conn) click to toggle source

Whether the connection is currently inside a savepoint.

    # File lib/sequel/database/transactions.rb
426 def in_savepoint?(conn)
427   supports_savepoints? && savepoint_level(conn) > 1
428 end
remove_transaction(conn, committed) click to toggle source

Remove the current thread from the list of active transactions

    # File lib/sequel/database/transactions.rb
446 def remove_transaction(conn, committed)
447   callbacks = transaction_hooks(conn, committed)
448   if in_savepoint?(conn)
449     savepoint_callbacks = savepoint_hooks(conn, committed)
450     if committed
451       savepoint_rollback_callbacks = savepoint_hooks(conn, false)
452     end
453   end
454 
455   if transaction_finished?(conn)
456     h = _trans(conn)
457     rolled_back = !committed
458     Sequel.synchronize{h[:rolled_back] = rolled_back}
459     Sequel.synchronize{@transactions.delete(conn)}
460   elsif savepoint_callbacks || savepoint_rollback_callbacks
461     if committed
462       meth = in_savepoint?(conn) ? :add_savepoint_hook : :add_transaction_hook 
463 
464       if savepoint_callbacks
465         savepoint_callbacks.each do |block|
466           send(meth, conn, :after_commit, block)
467         end
468       end
469       
470       if savepoint_rollback_callbacks
471         savepoint_rollback_callbacks.each do |block|
472           send(meth, conn, :after_rollback, block)
473         end
474       end
475     else
476       savepoint_callbacks.each(&:call)
477     end
478   end
479 
480   callbacks.each(&:call) if callbacks
481 end
rollback_on_transaction_exit?(conn, opts) click to toggle source

Whether to rollback the transaction when exiting the transaction.

    # File lib/sequel/database/transactions.rb
489 def rollback_on_transaction_exit?(conn, opts)
490   return true if Thread.current.status == 'aborting'
491   h = _trans(conn)
492   if supports_savepoints?
493     h[:savepoints].last[:rollback_on_exit]
494   else
495     h[:rollback_on_exit]
496   end
497 end
rollback_savepoint_sql(depth) click to toggle source

SQL to rollback to a savepoint

    # File lib/sequel/database/transactions.rb
484 def rollback_savepoint_sql(depth)
485   "ROLLBACK TO SAVEPOINT autopoint_#{depth}"
486 end
rollback_transaction(conn, opts=OPTS) click to toggle source

Rollback the active transaction on the connection

    # File lib/sequel/database/transactions.rb
500 def rollback_transaction(conn, opts=OPTS)
501   if supports_savepoints?
502     depth = savepoint_level(conn)
503     log_connection_execute(conn, depth > 1 ? rollback_savepoint_sql(depth-1) : rollback_transaction_sql)
504   else
505     log_connection_execute(conn, rollback_transaction_sql)
506   end
507 end
rollback_transaction_sql() click to toggle source

SQL to ROLLBACK a transaction.

    # File lib/sequel/database/transactions.rb
510 def rollback_transaction_sql
511   'ROLLBACK'
512 end
savepoint_hooks(conn, committed) click to toggle source

Retrieve the savepoint hooks that should be run for the given connection and commit status. This expacts that you are already inside a savepoint when calling.

    # File lib/sequel/database/transactions.rb
433 def savepoint_hooks(conn, committed)
434   _trans(conn)[:savepoints].last[committed ? :after_commit : :after_rollback]
435 end
savepoint_level(conn) click to toggle source

Current savepoint level.

    # File lib/sequel/database/transactions.rb
527 def savepoint_level(conn)
528   _trans(conn)[:savepoints].length
529 end
set_transaction_isolation(conn, opts) click to toggle source

Set the transaction isolation level on the given connection

    # File lib/sequel/database/transactions.rb
515 def set_transaction_isolation(conn, opts)
516   if supports_transaction_isolation_levels? and level = opts.fetch(:isolation, transaction_isolation_level)
517     log_connection_execute(conn, set_transaction_isolation_sql(level))
518   end
519 end
set_transaction_isolation_sql(level) click to toggle source

SQL to set the transaction isolation level

    # File lib/sequel/database/transactions.rb
522 def set_transaction_isolation_sql(level)
523   "SET TRANSACTION ISOLATION LEVEL #{TRANSACTION_ISOLATION_LEVELS[level]}"
524 end
transaction_error(e, opts=OPTS) click to toggle source

Raise a database error unless the exception is an Rollback.

    # File lib/sequel/database/transactions.rb
532 def transaction_error(e, opts=OPTS)
533   if e.is_a?(Rollback)
534     raise e if opts[:rollback] == :reraise
535   else
536     raise_error(e, opts.merge(:classes=>database_error_classes))
537   end
538 end
transaction_finished?(conn) click to toggle source

Finish a subtransaction. If savepoints are supported, pops the current tansaction off the savepoint stack.

    # File lib/sequel/database/transactions.rb
542 def transaction_finished?(conn)
543   if supports_savepoints?
544     stack = _trans(conn)[:savepoints]
545     stack.pop
546     stack.empty?
547   else
548     true
549   end
550 end
transaction_hooks(conn, committed) click to toggle source

Retrieve the transaction hooks that should be run for the given connection and commit status.

    # File lib/sequel/database/transactions.rb
439 def transaction_hooks(conn, committed)
440   unless in_savepoint?(conn)
441     _trans(conn)[committed ? :after_commit : :after_rollback]
442   end
443 end
transaction_options(conn, opts) click to toggle source

Derive the transaction hash from the options passed to the transaction. Meant to be overridden.

    # File lib/sequel/database/transactions.rb
341 def transaction_options(conn, opts)
342   {}
343 end

9 - Methods that describe what the database supports

↑ top

Public Instance Methods

global_index_namespace?() click to toggle source

Whether the database uses a global namespace for the index, true by default. If false, the indexes are going to be namespaced per table.

   # File lib/sequel/database/features.rb
13 def global_index_namespace?
14   true
15 end
supports_create_table_if_not_exists?() click to toggle source

Whether the database supports CREATE TABLE IF NOT EXISTS syntax, false by default.

   # File lib/sequel/database/features.rb
19 def supports_create_table_if_not_exists?
20   false
21 end
supports_deferrable_constraints?() click to toggle source

Whether the database supports deferrable constraints, false by default as few databases do.

   # File lib/sequel/database/features.rb
25 def supports_deferrable_constraints?
26   false
27 end
supports_deferrable_foreign_key_constraints?() click to toggle source

Whether the database supports deferrable foreign key constraints, false by default as few databases do.

   # File lib/sequel/database/features.rb
31 def supports_deferrable_foreign_key_constraints?
32   supports_deferrable_constraints?
33 end
supports_drop_table_if_exists?() click to toggle source

Whether the database supports DROP TABLE IF EXISTS syntax, false by default.

   # File lib/sequel/database/features.rb
37 def supports_drop_table_if_exists?
38   supports_create_table_if_not_exists?
39 end
supports_foreign_key_parsing?() click to toggle source

Whether the database supports Database#foreign_key_list for parsing foreign keys.

   # File lib/sequel/database/features.rb
43 def supports_foreign_key_parsing?
44   respond_to?(:foreign_key_list)
45 end
supports_index_parsing?() click to toggle source

Whether the database supports Database#indexes for parsing indexes.

   # File lib/sequel/database/features.rb
48 def supports_index_parsing?
49   respond_to?(:indexes)
50 end
supports_partial_indexes?() click to toggle source

Whether the database supports partial indexes (indexes on a subset of a table), false by default.

   # File lib/sequel/database/features.rb
54 def supports_partial_indexes?
55   false
56 end
supports_prepared_transactions?() click to toggle source

Whether the database and adapter support prepared transactions (two-phase commit), false by default.

   # File lib/sequel/database/features.rb
60 def supports_prepared_transactions?
61   false
62 end
supports_savepoints?() click to toggle source

Whether the database and adapter support savepoints, false by default.

   # File lib/sequel/database/features.rb
65 def supports_savepoints?
66   false
67 end
supports_savepoints_in_prepared_transactions?() click to toggle source

Whether the database and adapter support savepoints inside prepared transactions (two-phase commit), false by default.

   # File lib/sequel/database/features.rb
71 def supports_savepoints_in_prepared_transactions?
72   supports_prepared_transactions? && supports_savepoints?
73 end
supports_schema_parsing?() click to toggle source

Whether the database supports schema parsing via Database#schema.

   # File lib/sequel/database/features.rb
76 def supports_schema_parsing?
77   respond_to?(:schema_parse_table, true)
78 end
supports_table_listing?() click to toggle source

Whether the database supports Database#tables for getting list of tables.

   # File lib/sequel/database/features.rb
81 def supports_table_listing?
82   respond_to?(:tables)
83 end
supports_transaction_isolation_levels?() click to toggle source

Whether the database and adapter support transaction isolation levels, false by default.

   # File lib/sequel/database/features.rb
91 def supports_transaction_isolation_levels?
92   false
93 end
supports_transactional_ddl?() click to toggle source

Whether DDL statements work correctly in transactions, false by default.

   # File lib/sequel/database/features.rb
96 def supports_transactional_ddl?
97   false
98 end
supports_view_listing?() click to toggle source

Whether the database supports Database#views for getting list of views.

   # File lib/sequel/database/features.rb
86 def supports_view_listing?
87   respond_to?(:views)
88 end
supports_views_with_check_option?() click to toggle source

Whether CREATE VIEW … WITH CHECK OPTION is supported, false by default.

    # File lib/sequel/database/features.rb
101 def supports_views_with_check_option?
102   !!view_with_check_option_support
103 end
supports_views_with_local_check_option?() click to toggle source

Whether CREATE VIEW … WITH LOCAL CHECK OPTION is supported, false by default.

    # File lib/sequel/database/features.rb
106 def supports_views_with_local_check_option?
107   view_with_check_option_support == :local
108 end

Private Instance Methods

can_add_primary_key_constraint_on_nullable_columns?() click to toggle source

Whether the database supports adding primary key constraints on NULLable columns, automatically making them NOT NULL. If false, the columns must be set NOT NULL before the primary key constraint is added.

    # File lib/sequel/database/features.rb
115 def can_add_primary_key_constraint_on_nullable_columns?
116   true
117 end
folds_unquoted_identifiers_to_uppercase?() click to toggle source

Whether this dataset considers unquoted identifiers as uppercase. True by default as that is the SQL standard

    # File lib/sequel/database/features.rb
121 def folds_unquoted_identifiers_to_uppercase?
122   true
123 end
supports_combining_alter_table_ops?() click to toggle source

Whether the database supports combining multiple alter table operations into a single query, false by default.

    # File lib/sequel/database/features.rb
127 def supports_combining_alter_table_ops?
128   false
129 end
supports_create_or_replace_view?() click to toggle source

Whether the database supports CREATE OR REPLACE VIEW. If not, support will be emulated by dropping the view first. false by default.

    # File lib/sequel/database/features.rb
133 def supports_create_or_replace_view?
134   false
135 end
supports_named_column_constraints?() click to toggle source

Whether the database supports named column constraints. True by default. Those that don’t support named column constraints have to have column constraints converted to table constraints if the column constraints have names.

    # File lib/sequel/database/features.rb
141 def supports_named_column_constraints?
142   true
143 end
view_with_check_option_support() click to toggle source

Don’t advertise support for WITH CHECK OPTION by default.

    # File lib/sequel/database/features.rb
146 def view_with_check_option_support
147   nil
148 end