Represents a SQL table in an abstract way for updating a table. Also see TableDefinition and SchemaStatements#create_table
Available transformations are:
change_table :table do |t| t.column t.index t.timestamps t.change t.change_default t.rename t.references t.belongs_to t.string t.text t.integer t.float t.decimal t.datetime t.timestamp t.time t.date t.binary t.boolean t.remove t.remove_references t.remove_belongs_to t.remove_index t.remove_timestamps end
- belongs_to
- change
- change_default
- column
- index
- new
- references
- remove
- remove_belongs_to
- remove_index
- remove_references
- remove_timestamps
- rename
- timestamps
[ show source ]
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 567 567: def initialize(table_name, base) 568: @table_name = table_name 569: @base = base 570: end
Alias for references
Changes the column‘s definition according to the new options. See TableDefinition#column for details of the options you can use.
Examples
t.change(:name, :string, :limit => 80) t.change(:description, :text)
[ show source ]
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 607 607: def change(column_name, type, options = {}) 608: @base.change_column(@table_name, column_name, type, options) 609: end
Sets a new default value for a column. See SchemaStatements#change_column_default
Examples
t.change_default(:qualification, 'new') t.change_default(:authorized, 1)
[ show source ]
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 615 615: def change_default(column_name, default) 616: @base.change_column_default(@table_name, column_name, default) 617: end
Adds a new column to the named table. See TableDefinition#column for details of the options you can use.
Example
Creating a simple column
t.column(:name, :string)
[ show source ]
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 577 577: def column(column_name, type, options = {}) 578: @base.add_column(@table_name, column_name, type, options) 579: end
Adds a new index to the table. column_name can be a single Symbol, or an Array of Symbols. See SchemaStatements#add_index
Examples
Creating a simple index
t.index(:name)
Creating a unique index
t.index([:branch_id, :party_id], :unique => true)
Creating a named index
t.index([:branch_id, :party_id], :unique => true, :name => 'by_branch_party')
[ show source ]
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 591 591: def index(column_name, options = {}) 592: @base.add_index(@table_name, column_name, options) 593: end
Adds a reference. Optionally adds a type column. references and belongs_to are acceptable.
Examples
t.references(:goat) t.references(:goat, :polymorphic => true) t.belongs_to(:goat)
[ show source ]
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 662 662: def references(*args) 663: options = args.extract_options! 664: polymorphic = options.delete(:polymorphic) 665: args.each do |col| 666: @base.add_column(@table_name, "#{col}_id", :integer, options) 667: @base.add_column(@table_name, "#{col}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) unless polymorphic.nil? 668: end 669: end
Removes the column(s) from the table definition.
Examples
t.remove(:qualification) t.remove(:qualification, :experience)
[ show source ]
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 623 623: def remove(*column_names) 624: @base.remove_column(@table_name, column_names) 625: end
Alias for remove_references
Removes the given index from the table.
Examples
Remove the suppliers_name_index in the suppliers table
t.remove_index :name
Remove the index named accounts_branch_id_index in the accounts table
t.remove_index :column => :branch_id
Remove the index named accounts_branch_id_party_id_index in the accounts table
t.remove_index :column => [:branch_id, :party_id]
Remove the index named by_branch_party in the accounts table
t.remove_index :name => :by_branch_party
[ show source ]
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 638 638: def remove_index(options = {}) 639: @base.remove_index(@table_name, options) 640: end
Removes a reference. Optionally removes a type column. remove_references and remove_belongs_to are acceptable.
Examples
t.remove_references(:goat) t.remove_references(:goat, :polymorphic => true) t.remove_belongs_to(:goat)
[ show source ]
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 678 678: def remove_references(*args) 679: options = args.extract_options! 680: polymorphic = options.delete(:polymorphic) 681: args.each do |col| 682: @base.remove_column(@table_name, "#{col}_id") 683: @base.remove_column(@table_name, "#{col}_type") unless polymorphic.nil? 684: end 685: end
Removes the timestamp columns (created_at and updated_at) from the table.
Example
t.remove_timestamps
[ show source ]
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 645 645: def remove_timestamps 646: @base.remove_timestamps(@table_name) 647: end
[ show source ]
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 652 652: def rename(column_name, new_column_name) 653: @base.rename_column(@table_name, column_name, new_column_name) 654: end
Adds timestamps (created_at and updated_at) columns to the table. See SchemaStatements#add_timestamps
Example
t.timestamps
[ show source ]
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 598 598: def timestamps 599: @base.add_timestamps(@table_name) 600: end