class Sequel::Schema::CreateTableGenerator

Schema::CreateTableGenerator is an internal class that the user is not expected to instantiate directly. Instances are created by Database#create_table. It is used to specify table creation parameters. It takes a Database object and a block of column/index/constraint specifications, and gives the Database a table description, which the database uses to create a table.

Schema::CreateTableGenerator has some methods but also includes method_missing, allowing users to specify column type as a method instead of using the column method, which makes for a nicer DSL.

For more information on Sequel’s support for schema modification, see the “Schema Modification” guide.

Constants

GENERIC_TYPES

Classes specifying generic types that Sequel will convert to database-specific types.

Attributes

columns[R]

Column hashes created by this generator

constraints[R]

Constraint hashes created by this generator

indexes[R]

Index hashes created by this generator

Public Class Methods

add_type_method(*types) click to toggle source

Add a method for each of the given types that creates a column with that type as a constant. Types given should either already be constants/classes or a capitalized string/symbol with the same name as a constant/class.

   # File lib/sequel/database/schema_generator.rb
59 def self.add_type_method(*types)
60   types.each do |type|
61     case type
62     when Symbol, String
63       method = type
64       type = Object.const_get(type)
65     else
66       method = type.to_s
67     end
68 
69     define_method(method){|name, opts=OPTS| column(name, type, opts)}
70   end
71   nil
72 end
new(db, &block) click to toggle source

Set the database in which to create the table, and evaluate the block in the context of this object.

   # File lib/sequel/database/schema_generator.rb
34 def initialize(db, &block)
35   @db = db
36   @columns = []
37   @indexes = []
38   @constraints = []
39   @primary_key = nil
40   instance_exec(&block) if block
41 end

Public Instance Methods

Bignum(name, opts=OPTS) click to toggle source

Use custom Bignum method to use :Bignum instead of Bignum class, to work correctly in cases where Bignum is the same as Integer.

   # File lib/sequel/database/schema_generator.rb
45 def Bignum(name, opts=OPTS)
46   column(name, :Bignum, opts)
47 end
Fixnum(name, opts=OPTS) click to toggle source

Use custom Fixnum method to use Integer instead of Fixnum class, to avoid warnings on ruby 2.4+.

   # File lib/sequel/database/schema_generator.rb
51 def Fixnum(name, opts=OPTS)
52   column(name, Integer, opts)
53 end
check(*args, &block) click to toggle source

Add an unnamed constraint, specified by the given block or args:

check(num: 1..5) # CHECK num >= 1 AND num <= 5
check{num > 5}   # CHECK num > 5
   # File lib/sequel/database/schema_generator.rb
79 def check(*args, &block)
80   constraint(nil, *args, &block)
81 end
column(name, type, opts = OPTS) click to toggle source

Add a column with the given name, type, and opts:

column :num, :integer
# num INTEGER

column :name, String, null: false, default: 'a'
# name varchar(255) NOT NULL DEFAULT 'a'

inet :ip
# ip inet

You can also create columns via method missing, so the following are equivalent:

column :number, :integer
integer :number

The following options are supported:

:collate

The collation to use for the column. For backwards compatibility, only symbols and string values are supported, and they are used verbatim. However, on PostgreSQL, symbols are literalized as regular identifiers, since unquoted collations are unlikely to be valid.

:default

The default value for the column.

:deferrable

For foreign key columns, this ensures referential integrity will work even if referencing table uses a foreign key value that does not yet exist on referenced table (but will exist before the transaction commits). Basically it adds DEFERRABLE INITIALLY DEFERRED on key creation. If you use :immediate as the value, uses DEFERRABLE INITIALLY IMMEDIATE.

:generated_always_as

Specify a GENERATED ALWAYS AS column expression, if generated columns are supported (PostgreSQL 12+, MariaDB 5.2.0+, and MySQL 5.7.6+).

:index

Create an index on this column. If given a hash, use the hash as the options for the index.

:key

For foreign key columns, the column in the associated table that this column references. Unnecessary if this column references the primary key of the associated table, except if you are using MySQL.

:null

Mark the column as allowing NULL values (if true), or not allowing NULL values (if false). The default is to allow NULL values.

:on_delete

Specify the behavior of this column when being deleted (:restrict, :cascade, :set_null, :set_default, :no_action).

:on_update

Specify the behavior of this column when being updated (:restrict, :cascade, :set_null, :set_default, :no_action).

:primary_key

Make the column as a single primary key column. This should not be used if you want a single autoincrementing primary key column (use the primary_key method in that case).

:primary_key_constraint_name

The name to give the primary key constraint

:primary_key_deferrable

Similar to :deferrable, but for the primary key constraint if :primary_key is used.

:type

Overrides the type given as the argument. Generally not used by column itself, but can be passed as an option to other methods that call column.

:unique

Mark the column as unique, generally has the same effect as creating a unique index on the column.

:unique_constraint_name

The name to give the unique key constraint

:unique_deferrable

Similar to :deferrable, but for the unique constraint if :unique is used.

PostgreSQL specific options:

:identity

Create an identity column.

MySQL specific options:

:generated_type

Set the type of column when using :generated_always_as, should be :virtual or :stored to force a type.

:on_update_current_timestamp

Use ON UPDATE CURRENT TIMESTAMP when defining the column, which will update the column value to CURRENT_TIMESTAMP on every UPDATE.

Microsoft SQL Server specific options:

:clustered

When using :primary_key or :unique, marks the primary key or unique constraint as CLUSTERED (if true), or NONCLUSTERED (if false).

    # File lib/sequel/database/schema_generator.rb
157 def column(name, type, opts = OPTS)
158   columns << {:name => name, :type => type}.merge!(opts)
159   if index_opts = opts[:index]
160     index(name, index_opts.is_a?(Hash) ? index_opts : OPTS)
161   end
162   nil
163 end
constraint(name, *args, &block) click to toggle source

Adds a named CHECK constraint (or unnamed if name is nil), with the given block or args. To provide options for the constraint, pass a hash as the first argument.

constraint(:blah, num: 1..5)
# CONSTRAINT blah CHECK num >= 1 AND num <= 5
constraint({name: :blah, deferrable: true}, num: 1..5)
# CONSTRAINT blah CHECK num >= 1 AND num <= 5 DEFERRABLE INITIALLY DEFERRED

If the first argument is a hash, the following options are supported:

Options:

:name

The name of the CHECK constraint

:deferrable

Whether the CHECK constraint should be marked DEFERRABLE.

PostgreSQL specific options:

:not_valid

Whether the CHECK constraint should be marked NOT VALID.

    # File lib/sequel/database/schema_generator.rb
182 def constraint(name, *args, &block)
183   opts = name.is_a?(Hash) ? name : {:name=>name}
184   constraints << opts.merge(:type=>:check, :check=>block || args)
185   nil
186 end
dump_columns() click to toggle source

Dump this generator’s columns to a string that could be evaled inside another instance to represent the same columns

    # File lib/sequel/extensions/schema_dumper.rb
430 def dump_columns
431   strings = []
432   cols = columns.dup
433   cols.each do |x|
434     x.delete(:on_delete) if x[:on_delete] == :no_action
435     x.delete(:on_update) if x[:on_update] == :no_action
436   end
437   if (pkn = primary_key_name) && !@primary_key[:keep_order]
438     cols.delete_if{|x| x[:name] == pkn}
439     pk = @primary_key.dup
440     pkname = pk.delete(:name)
441     @db.serial_primary_key_options.each{|k,v| pk.delete(k) if v == pk[k]}
442     strings << "primary_key #{pkname.inspect}#{opts_inspect(pk)}"
443   end
444   cols.each do |c|
445     c = c.dup
446     name = c.delete(:name)
447     strings << if table = c.delete(:table)
448       c.delete(:type) if c[:type] == Integer || c[:type] == 'integer'
449       "foreign_key #{name.inspect}, #{table.inspect}#{opts_inspect(c)}"
450     elsif pkn == name
451       @db.serial_primary_key_options.each{|k,v| c.delete(k) if v == c[k]}
452       "primary_key #{name.inspect}#{opts_inspect(c)}"
453     else
454       type = c.delete(:type)
455       opts = opts_inspect(c)
456       case type
457       when Class
458         "#{type.name} #{name.inspect}#{opts}"
459       when :Bignum
460         "Bignum #{name.inspect}#{opts}"
461       else
462         "column #{name.inspect}, #{type.inspect}#{opts}"
463       end
464     end
465   end
466   strings.join("\n")
467 end
dump_constraints() click to toggle source

Dump this generator’s constraints to a string that could be evaled inside another instance to represent the same constraints

    # File lib/sequel/extensions/schema_dumper.rb
471 def dump_constraints
472   cs = constraints.map do |c|
473     c = c.dup
474     type = c.delete(:type)
475     case type
476     when :check
477       raise(Error, "can't dump check/constraint specified with Proc") if c[:check].is_a?(Proc)
478       name = c.delete(:name)
479       if !name and c[:check].length == 1 and c[:check].first.is_a?(Hash)
480         "check #{c[:check].first.inspect[1...-1]}"
481       else
482         "#{name ? "constraint #{name.inspect}," : 'check'} #{c[:check].map(&:inspect).join(', ')}"
483       end
484     when :foreign_key
485       c.delete(:on_delete) if c[:on_delete] == :no_action
486       c.delete(:on_update) if c[:on_update] == :no_action
487       c.delete(:deferrable) unless c[:deferrable]
488       cols = c.delete(:columns)
489       table = c.delete(:table)
490       "#{type} #{cols.inspect}, #{table.inspect}#{opts_inspect(c)}"
491     else
492       cols = c.delete(:columns)
493       "#{type} #{cols.inspect}#{opts_inspect(c)}"
494     end
495   end
496   cs.join("\n")
497 end
dump_indexes(options=OPTS) click to toggle source

Dump this generator’s indexes to a string that could be evaled inside another instance to represent the same indexes. Options:

:add_index

Use add_index instead of index, so the methods can be called outside of a generator but inside a migration. The value of this option should be the table name to use.

:drop_index

Same as add_index, but create drop_index statements.

:ignore_errors

Add the ignore_errors option to the outputted indexes

    # File lib/sequel/extensions/schema_dumper.rb
506 def dump_indexes(options=OPTS)
507   is = indexes.map do |c|
508     c = c.dup
509     cols = c.delete(:columns)
510     if table = options[:add_index] || options[:drop_index]
511       "#{options[:drop_index] ? 'drop' : 'add'}_index #{table.inspect}, #{cols.inspect}#{', :ignore_errors=>true' if options[:ignore_errors]}#{opts_inspect(c)}"
512     else
513       "index #{cols.inspect}#{opts_inspect(c)}"
514     end
515   end
516   is = is.reverse if options[:drop_index]
517   is.join("\n")
518 end
foreign_key(name, table=nil, opts = OPTS) click to toggle source

Add a foreign key in the table that references another table. See column for available options.

foreign_key(:artist_id) # artist_id INTEGER
foreign_key(:artist_id, :artists) # artist_id INTEGER REFERENCES artists
foreign_key(:artist_id, :artists, key: :id) # artist_id INTEGER REFERENCES artists(id)
foreign_key(:artist_id, :artists, type: String) # artist_id varchar(255) REFERENCES artists(id)

Additional Options:

:foreign_key_constraint_name

The name to give the foreign key constraint

If you want a foreign key constraint without adding a column (usually because it is a composite foreign key), you can provide an array of columns as the first argument, and you can provide the :name option to name the constraint:

foreign_key([:artist_name, :artist_location], :artists, name: :artist_fk)
# ADD CONSTRAINT artist_fk FOREIGN KEY (artist_name, artist_location) REFERENCES artists
    # File lib/sequel/database/schema_generator.rb
206 def foreign_key(name, table=nil, opts = OPTS)
207   opts = case table
208   when Hash
209     table.merge(opts)
210   when NilClass
211     opts
212   else
213     opts.merge(:table=>table)
214   end
215   return composite_foreign_key(name, opts) if name.is_a?(Array)
216   column(name, Integer, opts)
217 end
full_text_index(columns, opts = OPTS) click to toggle source

Add a full text index on the given columns. See index for additional options.

PostgreSQL specific options:

:index_type

Can be set to :gist to use a GIST index instead of the default GIN index.

:language

Set a language to use for the index (default: simple).

    # File lib/sequel/database/schema_generator.rb
226 def full_text_index(columns, opts = OPTS)
227   index(columns, opts.merge(:type => :full_text))
228 end
has_column?(name) click to toggle source

True if the generator includes the creation of a column with the given name.

    # File lib/sequel/database/schema_generator.rb
231 def has_column?(name)
232   columns.any?{|c| c[:name] == name}
233 end
index(columns, opts = OPTS) click to toggle source

Add an index on the given column(s) with the given options. Examples:

index :name
# CREATE INDEX table_name_index ON table (name)

index [:artist_id, :name]
# CREATE INDEX table_artist_id_name_index ON table (artist_id, name)

index [:artist_id, :name], name: :foo
# CREATE INDEX foo ON table (artist_id, name)

General options:

:include

Include additional column values in the index, without actually indexing on those values (only supported by some databases).

:name

The name to use for the index. If not given, a default name based on the table and columns is used.

:type

The type of index to use (only supported by some databases, :full_text and :spatial values are handled specially).

:unique

Make the index unique, so duplicate values are not allowed.

:where

A filter expression, used to create a partial index (only supported by some databases).

PostgreSQL specific options:

:concurrently

Create the index concurrently, so it doesn’t block operations on the table while the index is being built.

:if_not_exists

Only create the index if an index of the same name doesn’t already exist.

:nulls_distinct

Set whether separate NULLs should be considered distinct values in unique indexes.

:opclass

Set an opclass to use for all columns (per-column opclasses require custom SQL).

:tablespace

Specify tablespace for index.

Microsoft SQL Server specific options:

:key_index

Sets the KEY INDEX to the given value.

    # File lib/sequel/database/schema_generator.rb
273 def index(columns, opts = OPTS)
274   indexes << {:columns => Array(columns)}.merge!(opts)
275   nil
276 end
method_missing(type, name = nil, opts = OPTS) click to toggle source

Add a column with the given type, name, and opts. See column for available options.

Calls superclass method
    # File lib/sequel/database/schema_generator.rb
280 def method_missing(type, name = nil, opts = OPTS)
281   name ? column(name, type, opts) : super
282 end
primary_key(name, *args) click to toggle source

Adds an autoincrementing primary key column or a primary key constraint. To just create a constraint, the first argument should be an array of column symbols specifying the primary key columns. To create an autoincrementing primary key column, a single symbol can be used. In both cases, an options hash can be used as the second argument.

If you want to create a primary key column that is not autoincrementing, you should not use this method. Instead, you should use the regular column method with a primary_key: true option.

If an array of column symbols is used, you can specify the :name option to name the constraint.

Options:

:keep_order

For non-composite primary keys, respects the existing order of columns, overriding the default behavior of making the primary key the first column.

Examples:

primary_key(:id)
primary_key(:id, type: :Bignum, keep_order: true)
primary_key([:street_number, :house_number], name: :some_constraint_name)
    # File lib/sequel/database/schema_generator.rb
311 def primary_key(name, *args)
312   return composite_primary_key(name, *args) if name.is_a?(Array)
313   column = @db.serial_primary_key_options.merge({:name => name})
314   
315   if opts = args.pop
316     opts = {:type => opts} unless opts.is_a?(Hash)
317     if type = args.pop
318       opts = opts.merge(:type => type)
319     end
320     column.merge!(opts)
321   end
322 
323   @primary_key = column
324   if column[:keep_order]
325     columns << column
326   else
327     columns.unshift(column)
328   end
329   nil
330 end
primary_key_name() click to toggle source

The name of the primary key for this generator, if it has a primary key.

    # File lib/sequel/database/schema_generator.rb
333 def primary_key_name
334   @primary_key[:name] if @primary_key
335 end
respond_to_missing?(meth, include_private) click to toggle source

This object responds to all methods.

    # File lib/sequel/database/schema_generator.rb
285 def respond_to_missing?(meth, include_private)
286   true
287 end
spatial_index(columns, opts = OPTS) click to toggle source

Add a spatial index on the given columns. See index for additional options.

    # File lib/sequel/database/schema_generator.rb
339 def spatial_index(columns, opts = OPTS)
340   index(columns, opts.merge(:type => :spatial))
341 end
unique(columns, opts = OPTS) click to toggle source

Add a unique constraint on the given columns.

unique(:name) # UNIQUE (name)

Supports the same :deferrable option as column. The :name option can be used to name the constraint.

    # File lib/sequel/database/schema_generator.rb
349 def unique(columns, opts = OPTS)
350   constraints << {:type => :unique, :columns => Array(columns)}.merge!(opts)
351   nil
352 end

Private Instance Methods

composite_foreign_key(columns, opts) click to toggle source

Add a composite foreign key constraint

    # File lib/sequel/database/schema_generator.rb
364 def composite_foreign_key(columns, opts)
365   constraints << {:type => :foreign_key, :columns => columns}.merge!(opts)
366   nil
367 end
composite_primary_key(columns, *args) click to toggle source

Add a composite primary key constraint

    # File lib/sequel/database/schema_generator.rb
357 def composite_primary_key(columns, *args)
358   opts = args.pop || OPTS
359   constraints << {:type => :primary_key, :columns => columns}.merge!(opts)
360   nil
361 end
opts_inspect(opts) click to toggle source

Return a string that converts the given options into one suitable for literal ruby code, handling default values that don’t default to a literal interpretation.

    # File lib/sequel/extensions/schema_dumper.rb
525 def opts_inspect(opts)
526   if opts[:default]
527     opts = opts.dup
528     de = Sequel.eval_inspect(opts.delete(:default)) 
529     ", :default=>#{de}#{", #{opts.inspect[1...-1]}" if opts.length > 0}"
530   else
531     ", #{opts.inspect[1...-1]}" if opts.length > 0
532   end
533 end