class ActiveRecord::ConnectionAdapters::Table
Represents an SQL table in an abstract way for updating a table. Also see TableDefinition and ActiveRecord::ConnectionAdapters::SchemaStatements#create_table
Available transformations are:
change_table :table do |t| t.column t.index t.rename_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
Public Class Methods
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 350 def initialize(table_name, base) @table_name = table_name @base = base end
Public Instance Methods
Changes the column's definition according to the new options. See ActiveRecord::ConnectionAdapters::TableDefinition#column for details of the options you can use.
t.change(:name, :string, limit: 80) t.change(:description, :text)
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 406 def change(column_name, type, options = {}) @base.change_column(@table_name, column_name, type, options) end
Sets a new default value for a column. See ActiveRecord::ConnectionAdapters::SchemaStatements#change_column_default
t.change_default(:qualification, 'new') t.change_default(:authorized, 1)
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 414 def change_default(column_name, default) @base.change_column_default(@table_name, column_name, default) end
Adds a new column to the named table. See ActiveRecord::ConnectionAdapters::TableDefinition#column for details of the options you can use.
Creating a simple column
t.column(:name, :string)
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 360 def column(column_name, type, options = {}) @base.add_column(@table_name, column_name, type, options) end
Checks to see if a column exists. See ActiveRecord::ConnectionAdapters::SchemaStatements#column_exists?
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 365 def column_exists?(column_name, type = nil, options = {}) @base.column_exists?(@table_name, column_name, type, options) end
Adds a new index to the table. column_name
can be a single Symbol, or an Array of Symbols. See ActiveRecord::ConnectionAdapters::SchemaStatements#add_index
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')
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 378 def index(column_name, options = {}) @base.add_index(@table_name, column_name, options) end
Checks to see if an index exists. See ActiveRecord::ConnectionAdapters::SchemaStatements#index_exists?
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 383 def index_exists?(column_name, options = {}) @base.index_exists?(@table_name, column_name, options) end
Adds a reference. Optionally adds a type
column, if :polymorphic
option is provided. references
and belongs_to
are acceptable.
t.references(:user) t.belongs_to(:supplier, polymorphic: true)
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 460 def references(*args) options = args.extract_options! args.each do |ref_name| @base.add_reference(@table_name, ref_name, options) end end
Removes the column(s) from the table definition.
t.remove(:qualification) t.remove(:qualification, :experience)
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 422 def remove(*column_names) @base.remove_columns(@table_name, *column_names) end
Removes the given index from the table.
Remove the index_table_name_on_column in the table_name table
t.remove_index :column
Remove the index named index_table_name_on_branch_id in the table_name table
t.remove_index column: :branch_id
Remove the index named index_table_name_on_branch_id_and_party_id in the table_name table
t.remove_index column: [:branch_id, :party_id]
Remove the index named by_branch_party in the table_name table
t.remove_index name: :by_branch_party
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 436 def remove_index(options = {}) @base.remove_index(@table_name, options) end
Removes a reference. Optionally removes a type
column. remove_references
and remove_belongs_to
are acceptable.
t.remove_references(:user) t.remove_belongs_to(:supplier, polymorphic: true)
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 474 def remove_references(*args) options = args.extract_options! args.each do |ref_name| @base.remove_reference(@table_name, ref_name, options) end end
Removes the timestamp columns (created_at
and updated_at
) from the table.
t.remove_timestamps
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 443 def remove_timestamps @base.remove_timestamps(@table_name) end
Renames a column.
t.rename(:description, :name)
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 450 def rename(column_name, new_column_name) @base.rename_column(@table_name, column_name, new_column_name) end
Renames the given index on the table.
t.rename_index(:user_id, :account_id)
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 390 def rename_index(index_name, new_index_name) @base.rename_index(@table_name, index_name, new_index_name) end
Adds timestamps (created_at
and updated_at
) columns to the table. See ActiveRecord::ConnectionAdapters::SchemaStatements#add_timestamps
t.timestamps
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 397 def timestamps(options = {}) @base.add_timestamps(@table_name, options) end
© 2004–2016 David Heinemeier Hansson
Licensed under the MIT License.