class Sequel::Schema::CreateTableGenerator

  1. lib/sequel/database/schema_generator.rb
Superclass: Object

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 = %w'String Integer Float Numeric BigDecimal Date DateTime Time File TrueClass FalseClass'.freeze  

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)

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.

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

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

[show source]
   # 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   @columns.unshift(@primary_key) if @primary_key && !has_column?(primary_key_name)
42 end

Public Instance methods

Bignum (name, opts=OPTS)

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

[show source]
   # File lib/sequel/database/schema_generator.rb
46 def Bignum(name, opts=OPTS)
47   column(name, :Bignum, opts)
48 end
Fixnum (name, opts=OPTS)

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

[show source]
   # File lib/sequel/database/schema_generator.rb
52 def Fixnum(name, opts=OPTS)
53   column(name, Integer, opts)
54 end
check (*args, &block)

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
[show source]
   # File lib/sequel/database/schema_generator.rb
80 def check(*args, &block)
81   constraint(nil, *args, &block)
82 end
column (name, type, opts = OPTS)

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 have a single, nonautoincrementing 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.

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

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
[show source]
    # File lib/sequel/database/schema_generator.rb
165 def constraint(name, *args, &block)
166   opts = name.is_a?(Hash) ? name : {:name=>name}
167   constraints << opts.merge(:type=>:check, :check=>block || args)
168   nil
169 end
foreign_key (name, table=nil, opts = OPTS)

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
[show source]
    # File lib/sequel/database/schema_generator.rb
189 def foreign_key(name, table=nil, opts = OPTS)
190   opts = case table
191   when Hash
192     table.merge(opts)
193   when NilClass
194     opts
195   else
196     opts.merge(:table=>table)
197   end
198   return composite_foreign_key(name, opts) if name.is_a?(Array)
199   column(name, Integer, opts)
200 end
full_text_index (columns, opts = OPTS)

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.

[show source]
    # File lib/sequel/database/schema_generator.rb
211 def full_text_index(columns, opts = OPTS)
212   index(columns, opts.merge(:type => :full_text))
213 end
has_column? (name)

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

[show source]
    # File lib/sequel/database/schema_generator.rb
216 def has_column?(name)
217   columns.any?{|c| c[:name] == name}
218 end
index (columns, opts = OPTS)

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)
[show source]
    # File lib/sequel/database/schema_generator.rb
249 def index(columns, opts = OPTS)
250   indexes << {:columns => Array(columns)}.merge!(opts)
251   nil
252 end
method_missing (type, name = nil, opts = OPTS)

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

[show source]
    # File lib/sequel/database/schema_generator.rb
256 def method_missing(type, name = nil, opts = OPTS)
257   name ? column(name, type, opts) : super
258 end
primary_key (name, *args)

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)
[show source]
    # File lib/sequel/database/schema_generator.rb
287 def primary_key(name, *args)
288   return composite_primary_key(name, *args) if name.is_a?(Array)
289   column = @db.serial_primary_key_options.merge({:name => name})
290   
291   if opts = args.pop
292     opts = {:type => opts} unless opts.is_a?(Hash)
293     if type = args.pop
294       opts = opts.merge(:type => type)
295     end
296     column.merge!(opts)
297   end
298 
299   @primary_key = column
300   if column[:keep_order]
301     columns << column
302   else
303     columns.unshift(column)
304   end
305   nil
306 end
primary_key_name ()

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

[show source]
    # File lib/sequel/database/schema_generator.rb
309 def primary_key_name
310   @primary_key[:name] if @primary_key
311 end
respond_to_missing? (meth, include_private)

This object responds to all methods.

[show source]
    # File lib/sequel/database/schema_generator.rb
261 def respond_to_missing?(meth, include_private)
262   true
263 end
spatial_index (columns, opts = OPTS)

Add a spatial index on the given columns.

[show source]
    # File lib/sequel/database/schema_generator.rb
314 def spatial_index(columns, opts = OPTS)
315   index(columns, opts.merge(:type => :spatial))
316 end
unique (columns, opts = OPTS)

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.

[show source]
    # File lib/sequel/database/schema_generator.rb
324 def unique(columns, opts = OPTS)
325   constraints << {:type => :unique, :columns => Array(columns)}.merge!(opts)
326   nil
327 end