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
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)

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 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
45 def Bignum(name, opts=OPTS)
46   column(name, :Bignum, opts)
47 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
51 def Fixnum(name, opts=OPTS)
52   column(name, Integer, opts)
53 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
79 def check(*args, &block)
80   constraint(nil, *args, &block)
81 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 want a single autoincrementing primary key column (use the primary_key method in that case). Can be a hash to provide options for the constraint:

:name

The name to give the primary key constraint.

:deferrable

Sets whether the primary key constraint is deferrable.

:primary_key_constraint_name

Older option to name primary key constraint.

:primary_key_deferrable

Older option to set primary key constraint as deferrable.

: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. Can be a hash to provide options for the constraint:

:name

The name to give the unique constraint.

:deferrable

Sets whether the unique constraint is deferrable.

:unique_constraint_name

Older option to name unique constraint.

:unique_deferrable

Older option to set unique constraint as deferrable.

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).

[show source]
    # File lib/sequel/database/schema_generator.rb
161 def column(name, type, opts = OPTS)
162   columns << {:name => name, :type => type}.merge!(opts)
163   if index_opts = opts[:index]
164     index(name, index_opts.is_a?(Hash) ? index_opts : OPTS)
165   end
166   nil
167 end
constraint(name, *args, &block)

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_enforced

Whether the CHECK constraint should be marked NOT ENFORCED.

:not_valid

Whether the CHECK constraint should be marked NOT VALID.

[show source]
    # File lib/sequel/database/schema_generator.rb
187 def constraint(name, *args, &block)
188   opts = name.is_a?(Hash) ? name : {:name=>name}
189   constraints << opts.merge(:type=>:check, :check=>block || args)
190   nil
191 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

PostgreSQL specific options:

:not_enforced

Whether the foreign key constraint should be marked NOT ENFORCED.

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. This changes the method to accept constraint options instead of column options. You can provide the :name option to name the constraint.

PostgreSQL specific options:

:not_enforced

Whether the foreign key constraint should be marked NOT ENFORCED.

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
220 def foreign_key(name, table=nil, opts = OPTS)
221   opts = case table
222   when Hash
223     table.merge(opts)
224   when NilClass
225     opts
226   else
227     opts.merge(:table=>table)
228   end
229   return composite_foreign_key(name, opts) if name.is_a?(Array)
230   column(name, Integer, opts)
231 end
full_text_index(columns, opts = OPTS)

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).

[show source]
    # File lib/sequel/database/schema_generator.rb
240 def full_text_index(columns, opts = OPTS)
241   index(columns, opts.merge(:type => :full_text))
242 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
245 def has_column?(name)
246   columns.any?{|c| c[:name] == name}
247 end
index(columns, opts = OPTS)

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.

[show source]
    # File lib/sequel/database/schema_generator.rb
287 def index(columns, opts = OPTS)
288   indexes << {:columns => Array(columns)}.merge!(opts)
289   nil
290 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
294 def method_missing(type, name = nil, opts = OPTS)
295   name ? column(name, type, opts) : super
296 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
325 def primary_key(name, *args)
326   return composite_primary_key(name, *args) if name.is_a?(Array)
327   column = @db.serial_primary_key_options.merge({:name => name})
328   
329   if opts = args.pop
330     opts = {:type => opts} unless opts.is_a?(Hash)
331     if type = args.pop
332       opts = opts.merge(:type => type)
333     end
334     column.merge!(opts)
335   end
336 
337   @primary_key = column
338   if column[:keep_order]
339     columns << column
340   else
341     columns.unshift(column)
342   end
343   nil
344 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
347 def primary_key_name
348   @primary_key[:name] if @primary_key
349 end
respond_to_missing?(meth, include_private)

This object responds to all methods.

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

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

[show source]
    # File lib/sequel/database/schema_generator.rb
353 def spatial_index(columns, opts = OPTS)
354   index(columns, opts.merge(:type => :spatial))
355 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
363 def unique(columns, opts = OPTS)
364   constraints << {:type => :unique, :columns => Array(columns)}.merge!(opts)
365   nil
366 end