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.

    # File lib/sequel/database/schema_generator.rb
148 def column(name, type, opts = OPTS)
149   columns << {:name => name, :type => type}.merge!(opts)
150   if index_opts = opts[:index]
151     index(name, index_opts.is_a?(Hash) ? index_opts : OPTS)
152   end
153   nil
154 end
constraint(name, *args, &block) click to toggle source

Adds a named 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
    # File lib/sequel/database/schema_generator.rb
164 def constraint(name, *args, &block)
165   opts = name.is_a?(Hash) ? name : {:name=>name}
166   constraints << opts.merge(:type=>:check, :check=>block || args)
167   nil
168 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
396 def dump_columns
397   strings = []
398   cols = columns.dup
399   cols.each do |x|
400     x.delete(:on_delete) if x[:on_delete] == :no_action
401     x.delete(:on_update) if x[:on_update] == :no_action
402   end
403   if (pkn = primary_key_name) && !@primary_key[:keep_order]
404     cols.delete_if{|x| x[:name] == pkn}
405     pk = @primary_key.dup
406     pkname = pk.delete(:name)
407     @db.serial_primary_key_options.each{|k,v| pk.delete(k) if v == pk[k]}
408     strings << "primary_key #{pkname.inspect}#{opts_inspect(pk)}"
409   end
410   cols.each do |c|
411     c = c.dup
412     name = c.delete(:name)
413     strings << if table = c.delete(:table)
414       c.delete(:type) if c[:type] == Integer || c[:type] == 'integer'
415       "foreign_key #{name.inspect}, #{table.inspect}#{opts_inspect(c)}"
416     elsif pkn == name
417       @db.serial_primary_key_options.each{|k,v| c.delete(k) if v == c[k]}
418       "primary_key #{name.inspect}#{opts_inspect(c)}"
419     else
420       type = c.delete(:type)
421       opts = opts_inspect(c)
422       case type
423       when Class
424         "#{type.name} #{name.inspect}#{opts}"
425       when :Bignum
426         "Bignum #{name.inspect}#{opts}"
427       else
428         "column #{name.inspect}, #{type.inspect}#{opts}"
429       end
430     end
431   end
432   strings.join("\n")
433 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
437 def dump_constraints
438   cs = constraints.map do |c|
439     c = c.dup
440     type = c.delete(:type)
441     case type
442     when :check
443       raise(Error, "can't dump check/constraint specified with Proc") if c[:check].is_a?(Proc)
444       name = c.delete(:name)
445       if !name and c[:check].length == 1 and c[:check].first.is_a?(Hash)
446         "check #{c[:check].first.inspect[1...-1]}"
447       else
448         "#{name ? "constraint #{name.inspect}," : 'check'} #{c[:check].map(&:inspect).join(', ')}"
449       end
450     when :foreign_key
451       c.delete(:on_delete) if c[:on_delete] == :no_action
452       c.delete(:on_update) if c[:on_update] == :no_action
453       c.delete(:deferrable) unless c[:deferrable]
454       cols = c.delete(:columns)
455       table = c.delete(:table)
456       "#{type} #{cols.inspect}, #{table.inspect}#{opts_inspect(c)}"
457     else
458       cols = c.delete(:columns)
459       "#{type} #{cols.inspect}#{opts_inspect(c)}"
460     end
461   end
462   cs.join("\n")
463 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
472 def dump_indexes(options=OPTS)
473   is = indexes.map do |c|
474     c = c.dup
475     cols = c.delete(:columns)
476     if table = options[:add_index] || options[:drop_index]
477       "#{options[:drop_index] ? 'drop' : 'add'}_index #{table.inspect}, #{cols.inspect}#{', :ignore_errors=>true' if options[:ignore_errors]}#{opts_inspect(c)}"
478     else
479       "index #{cols.inspect}#{opts_inspect(c)}"
480     end
481   end
482   is = is.reverse if options[:drop_index]
483   is.join("\n")
484 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
188 def foreign_key(name, table=nil, opts = OPTS)
189   opts = case table
190   when Hash
191     table.merge(opts)
192   when NilClass
193     opts
194   else
195     opts.merge(:table=>table)
196   end
197   return composite_foreign_key(name, opts) if name.is_a?(Array)
198   column(name, Integer, opts)
199 end
full_text_index(columns, opts = OPTS) click to toggle source

Add a full text index on the given columns.

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).

Microsoft SQL Server specific options:

:key_index

The KEY INDEX to use for the full text index.

    # File lib/sequel/database/schema_generator.rb
210 def full_text_index(columns, opts = OPTS)
211   index(columns, opts.merge(:type => :full_text))
212 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
215 def has_column?(name)
216   columns.any?{|c| c[:name] == name}
217 end
index(columns, opts = OPTS) click to toggle source

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

: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)

:unique

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

:where

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.

:opclass

Use a specific operator class in the index.

:include

Include additional column values in the index, without actually indexing on those values (PostgreSQL 11+).

:tablespace

Specify tablespace for index.

Microsoft SQL Server specific options:

:include

Include additional column values in the index, without actually indexing on those values.

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)
    # File lib/sequel/database/schema_generator.rb
248 def index(columns, opts = OPTS)
249   indexes << {:columns => Array(columns)}.merge!(opts)
250   nil
251 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
255 def method_missing(type, name = nil, opts = OPTS)
256   name ? column(name, type, opts) : super
257 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
286 def primary_key(name, *args)
287   return composite_primary_key(name, *args) if name.is_a?(Array)
288   column = @db.serial_primary_key_options.merge({:name => name})
289   
290   if opts = args.pop
291     opts = {:type => opts} unless opts.is_a?(Hash)
292     if type = args.pop
293       opts = opts.merge(:type => type)
294     end
295     column.merge!(opts)
296   end
297 
298   @primary_key = column
299   if column[:keep_order]
300     columns << column
301   else
302     columns.unshift(column)
303   end
304   nil
305 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
308 def primary_key_name
309   @primary_key[:name] if @primary_key
310 end
respond_to_missing?(meth, include_private) click to toggle source

This object responds to all methods.

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

Add a spatial index on the given columns.

    # File lib/sequel/database/schema_generator.rb
313 def spatial_index(columns, opts = OPTS)
314   index(columns, opts.merge(:type => :spatial))
315 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
323 def unique(columns, opts = OPTS)
324   constraints << {:type => :unique, :columns => Array(columns)}.merge!(opts)
325   nil
326 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
338 def composite_foreign_key(columns, opts)
339   constraints << {:type => :foreign_key, :columns => columns}.merge!(opts)
340   nil
341 end
composite_primary_key(columns, *args) click to toggle source

Add a composite primary key constraint

    # File lib/sequel/database/schema_generator.rb
331 def composite_primary_key(columns, *args)
332   opts = args.pop || OPTS
333   constraints << {:type => :primary_key, :columns => columns}.merge!(opts)
334   nil
335 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
491 def opts_inspect(opts)
492   if opts[:default]
493     opts = opts.dup
494     de = Sequel.eval_inspect(opts.delete(:default)) 
495     ", :default=>#{de}#{", #{opts.inspect[1...-1]}" if opts.length > 0}"
496   else
497     ", #{opts.inspect[1...-1]}" if opts.length > 0
498   end
499 end