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 "Migrations and Schema Modification" guide.

### Methods

add_type_method check column constraint foreign_key full_text_index has_column? index method_missing new primary_key primary_key_name spatial_index unique

### 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_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.

[Source]

        # File lib/sequel/database/schema_generator.rb, line 47
    47:       def self.add_type_method(*types)
    48:         types.each do |type|
    49:           class_eval("def #{type}(name, opts={}); column(name, #{type}, opts); end", __FILE__, __LINE__)
    50:         end
    51:       end

new(db, &block)

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

check(*args, &block)

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 58
    58:       def check(*args, &block)
    59:         constraint(nil, *args, &block)
    60:       end

column(name, type, opts = {})

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 : | This ensure Referential Integrity will work even if reference table will use for its foreign key a value that does not exists(yet) on referenced table. Basically it adds DEFERRABLE INITIALLY DEFERRED on key creation.
: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.
: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.

[Source]

         # File lib/sequel/database/schema_generator.rb, line 105
    105:       def column(name, type, opts = {})
    106:         columns << {:name => name, :type => type}.merge(opts)
    107:         if index_opts = opts[:index]
    108:           index(name, index_opts.is_a?(Hash) ? index_opts : {})
    109:         end
    110:       end

constraint(name, *args, &block)

Adds a named constraint (or unnamed if name is nil) to the DDL, with the given block or args.

      constraint(:blah, :num=>1..5) # CONSTRAINT blah CHECK num >= 1 AND num <= 5
      check(:foo){num > 5} # CONSTRAINT foo CHECK num > 5

[Source]

         # File lib/sequel/database/schema_generator.rb, line 117
    117:       def constraint(name, *args, &block)
    118:         constraints << {:name => name, :type => :check, :check => block || args}
    119:       end

foreign_key(name, table=nil, opts = {})

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)

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 135
    135:       def foreign_key(name, table=nil, opts = {})
    136:         opts = case table
    137:         when Hash
    138:           table.merge(opts)
    139:         when Symbol
    140:           opts.merge(:table=>table)
    141:         when NilClass
    142:           opts
    143:         else
    144:           raise(Error, "The second argument to foreign_key should be a Hash, Symbol, or nil")
    145:         end
    146:         return composite_foreign_key(name, opts) if name.is_a?(Array)
    147:         column(name, Integer, opts)
    148:       end

full_text_index(columns, opts = {})

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

PostgreSQL specific options:

: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 157
    157:       def full_text_index(columns, opts = {})
    158:         index(columns, opts.merge(:type => :full_text))
    159:       end

has_column?(name)

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

[Source]

         # File lib/sequel/database/schema_generator.rb, line 162
    162:       def has_column?(name)
    163:         columns.any?{|c| c[:name] == name}
    164:       end

index(columns, opts = {})

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.
:op_class : | 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 192
    192:       def index(columns, opts = {})
    193:         indexes << {:columns => Array(columns)}.merge(opts)
    194:       end

method_missing(type, name = nil, opts = {})

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 198
    198:       def method_missing(type, name = nil, opts = {})
    199:         name ? column(name, type, opts) : super
    200:       end

primary_key(name, *args)

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

Examples:

      primary_key(:id)
      primary_key([:street_number, :house_number])

[Source]

         # File lib/sequel/database/schema_generator.rb, line 215
    215:       def primary_key(name, *args)
    216:         return composite_primary_key(name, *args) if name.is_a?(Array)
    217:         @primary_key = @db.serial_primary_key_options.merge({:name => name})
    218:
    219:         if opts = args.pop
    220:           opts = {:type => opts} unless opts.is_a?(Hash)
    221:           if type = args.pop
    222:             opts.merge!(:type => type)
    223:           end
    224:           @primary_key.merge!(opts)
    225:         end
    226:         @primary_key
    227:       end

primary_key_name()

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

[Source]

         # File lib/sequel/database/schema_generator.rb, line 230
    230:       def primary_key_name
    231:         @primary_key[:name] if @primary_key
    232:       end

spatial_index(columns, opts = {})

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

[Source]

         # File lib/sequel/database/schema_generator.rb, line 235
    235:       def spatial_index(columns, opts = {})
    236:         index(columns, opts.merge(:type => :spatial))
    237:       end

unique(columns, opts = {})

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

      unique(:name) # UNIQUE (name)

[Source]

         # File lib/sequel/database/schema_generator.rb, line 242
    242:       def unique(columns, opts = {})
    243:         constraints << {:type => :unique, :columns => Array(columns)}.merge(opts)
    244:       end

[Validate]