Class Sequel::Schema::CreateTableGenerator
In: lib/sequel/database/schema_generator.rb
Parent: 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.

Methods

Constants

GENERIC_TYPES = [String, Integer, Fixnum, Bignum, Float, Numeric, BigDecimal, Date, DateTime, Time, File, TrueClass, FalseClass]   Classes specifying generic types that Sequel will convert to database-specific types.

Attributes

columns  [R]  Return the column hashes created by this generator
constraints  [R]  Return the constraint hashes created by this generator
indexes  [R]  Return the index hashes created by this generator

Public Class methods

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.

Do not call this method with untrusted input, as that can result in arbitrary code execution.

[Source]

    # File lib/sequel/database/schema_generator.rb, line 50
50:       def self.add_type_method(*types)
51:         types.each do |type|
52:           class_eval("def #{type}(name, opts={}); column(name, #{type}, opts); end", __FILE__, __LINE__)
53:         end
54:       end

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

[Source]

    # File lib/sequel/database/schema_generator.rb, line 33
33:       def initialize(db, &block)
34:         @db = db
35:         @columns = []
36:         @indexes = []
37:         @constraints = []
38:         @primary_key = nil
39:         instance_eval(&block) if block
40:         @columns.unshift(@primary_key) if @primary_key && !has_column?(primary_key_name)
41:       end

Public Instance methods

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

  check(:num=>1..5) # CHECK num >= 1 AND num <= 5
  check{num > 5} # CHECK num > 5

[Source]

    # File lib/sequel/database/schema_generator.rb, line 61
61:       def check(*args, &block)
62:         constraint(nil, *args, &block)
63:       end

Add a column with the given name, type, and opts to the DDL.

  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:

: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.
: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). If unspecified, will default to whatever the database default is.
: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 only be used if you have a single, nonautoincrementing primary key column.
:primary_key_constraint_name :The name to give the primary key constraint
: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

[Source]

     # File lib/sequel/database/schema_generator.rb, line 111
111:       def column(name, type, opts = OPTS)
112:         columns << {:name => name, :type => type}.merge(opts)
113:         if index_opts = opts[:index]
114:           index(name, index_opts.is_a?(Hash) ? index_opts : {})
115:         end
116:       end

Adds a named constraint (or unnamed if name is nil) to the DDL, 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

[Source]

     # File lib/sequel/database/schema_generator.rb, line 126
126:       def constraint(name, *args, &block)
127:         opts = name.is_a?(Hash) ? name : {:name=>name}
128:         constraints << opts.merge(:type=>:check, :check=>block || args)
129:       end

Add a foreign key in the table that references another table to the DDL. 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

[Source]

     # File lib/sequel/database/schema_generator.rb, line 149
149:       def foreign_key(name, table=nil, opts = OPTS)
150:         opts = case table
151:         when Hash
152:           table.merge(opts)
153:         when Symbol
154:           opts.merge(:table=>table)
155:         when NilClass
156:           opts
157:         else
158:           raise(Error, "The second argument to foreign_key should be a Hash, Symbol, or nil")
159:         end
160:         return composite_foreign_key(name, opts) if name.is_a?(Array)
161:         column(name, Integer, opts)
162:       end

Add a full text index on the given columns to the DDL.

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.

[Source]

     # File lib/sequel/database/schema_generator.rb, line 173
173:       def full_text_index(columns, opts = OPTS)
174:         index(columns, opts.merge(:type => :full_text))
175:       end

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

[Source]

     # File lib/sequel/database/schema_generator.rb, line 178
178:       def has_column?(name)
179:         columns.any?{|c| c[:name] == name}
180:       end

Add an index on the given column(s) with the given options to the DDL. 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.

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)

[Source]

     # File lib/sequel/database/schema_generator.rb, line 208
208:       def index(columns, opts = OPTS)
209:         indexes << {:columns => Array(columns)}.merge(opts)
210:       end

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

[Source]

     # File lib/sequel/database/schema_generator.rb, line 214
214:       def method_missing(type, name = nil, opts = OPTS)
215:         name ? column(name, type, opts) : super
216:       end

Adds an autoincrementing primary key column or a primary key constraint to the DDL. 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.

Examples:

  primary_key(:id)
  primary_key([:street_number, :house_number], :name=>:some constraint_name)

[Source]

     # File lib/sequel/database/schema_generator.rb, line 239
239:       def primary_key(name, *args)
240:         return composite_primary_key(name, *args) if name.is_a?(Array)
241:         @primary_key = @db.serial_primary_key_options.merge({:name => name})
242:         
243:         if opts = args.pop
244:           opts = {:type => opts} unless opts.is_a?(Hash)
245:           if type = args.pop
246:             opts.merge!(:type => type)
247:           end
248:           @primary_key.merge!(opts)
249:         end
250:         @primary_key
251:       end

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

[Source]

     # File lib/sequel/database/schema_generator.rb, line 254
254:       def primary_key_name
255:         @primary_key[:name] if @primary_key
256:       end

This object responds to all methods.

[Source]

     # File lib/sequel/database/schema_generator.rb, line 219
219:       def respond_to_missing?(meth, include_private)
220:         true
221:       end

Add a spatial index on the given columns to the DDL.

[Source]

     # File lib/sequel/database/schema_generator.rb, line 259
259:       def spatial_index(columns, opts = OPTS)
260:         index(columns, opts.merge(:type => :spatial))
261:       end

Add a unique constraint on the given columns to the DDL.

  unique(:name) # UNIQUE (name)

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

[Source]

     # File lib/sequel/database/schema_generator.rb, line 269
269:       def unique(columns, opts = OPTS)
270:         constraints << {:type => :unique, :columns => Array(columns)}.merge(opts)
271:       end

[Validate]