# File lib/sequel/database/schema_methods.rb 933 def primary_key_constraint_sql_fragment(_) 934 'PRIMARY KEY' 935 end
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
↑ topConstants
- 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
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.
The prepared statement object hash for this database, keyed by name symbol
Public Instance Methods
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 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
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
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
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
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
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
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
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
Uncached version of metadata_dataset
, designed for overriding.
# File lib/sequel/database/query.rb 362 def _metadata_dataset 363 dataset 364 end
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
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
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
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
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
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
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
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
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
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
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
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 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
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
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
↑ topConstants
- 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
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
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
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
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 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
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
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
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
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
, andany
. Theany
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
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
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
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
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
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
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 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
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
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
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
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
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
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 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
# 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
# File lib/sequel/database/schema_methods.rb 498 def alter_table_add_constraint_sql(table, op) 499 "ADD #{constraint_definition_sql(op)}" 500 end
# 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
# 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
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
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
# 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
# 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
# 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
# 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
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
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 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 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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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 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
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
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
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
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
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
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
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
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
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
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
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
Add fragment for primary key specification, separated for easier overridding.
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
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
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
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
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 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
SQL fragment for temporary table
# File lib/sequel/database/schema_methods.rb 968 def temporary_table_sql 969 'TEMPORARY ' 970 end
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
↑ topPublic Instance Methods
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
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
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
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
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
↑ topConstants
- ADAPTERS
Array
of supported database adapters
Attributes
Public Class Methods
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
Returns the scheme symbol for the Database
class.
# File lib/sequel/database/connecting.rb 21 def self.adapter_scheme 22 @scheme 23 end
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 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
Public Instance Methods
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
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
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
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
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
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
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
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
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
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
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
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
The default options for the connection pool.
# File lib/sequel/database/connecting.rb 313 def connection_pool_default_options 314 {} 315 end
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
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
↑ topAttributes
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
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
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
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
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 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
↑ topAttributes
Whether to include information about the connection in use when logging queries.
Numeric
specifying the duration beyond which queries are logged at warn level instead of info level.
Array
of SQL loggers to use for this database.
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
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 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 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
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
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 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 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 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
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
↑ topConstants
- 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 theDatabase
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
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.
The specific default size of string columns for this Sequel::Database
, usually 255 by default.
The options hash for this database
Set the timezone to use for this database, overridding Sequel.database_timezone
.
Public Class Methods
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
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
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 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 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
# 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
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 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
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 internal data structures for the Database
instance.
# 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
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
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
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
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
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
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
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
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
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
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
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
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
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 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
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
Explicit alias of uri for easier subclassing.
# File lib/sequel/database/misc.rb 375 def url 376 uri 377 end
Private Instance Methods
: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
Per adapter initialization method, empty by default.
# File lib/sequel/database/misc.rb 382 def adapter_initialize 383 end
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
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
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
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
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
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
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
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
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 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
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
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 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 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 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 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 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 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 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 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 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
9 - Methods that describe what the database supports
↑ topPublic Instance Methods
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
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
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
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
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
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
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
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
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
Whether the database and adapter support savepoints, false by default.
# File lib/sequel/database/features.rb 65 def supports_savepoints? 66 false 67 end
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
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
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
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
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
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
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
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
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
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
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
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
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
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