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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
Methods
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Class Public methods
new(table_name, base)
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 408
def initialize(table_name, base)
  @table_name = table_name
  @base = base
end
Instance Public methods
belongs_to(*args)
Alias for: references
change(column_name, type, options = {})

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 464
def change(column_name, type, options = {})
  @base.change_column(@table_name, column_name, type, options)
end
change_default(column_name, default)

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 472
def change_default(column_name, default)
  @base.change_column_default(@table_name, column_name, default)
end
column(column_name, type, options = {})

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 418
def column(column_name, type, options = {})
  @base.add_column(@table_name, column_name, type, options)
end
column_exists?(column_name, type = nil, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 423
def column_exists?(column_name, type = nil, options = {})
  @base.column_exists?(@table_name, column_name, type, options)
end
index(column_name, options = {})

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 436
def index(column_name, options = {})
  @base.add_index(@table_name, column_name, options)
end
index_exists?(column_name, options = {})
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 441
def index_exists?(column_name, options = {})
  @base.index_exists?(@table_name, column_name, options)
end
references(*args)

Adds a reference. Optionally adds a type column, if :polymorphic option is provided. references and belongs_to are acceptable. The reference column will be an integer by default, the :type option can be used to specify a different type.

t.references(:user)
t.references(:user, type: "string")
t.belongs_to(:supplier, polymorphic: true)

See ActiveRecord::ConnectionAdapters::SchemaStatements#add_reference

Also aliased as: belongs_to
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 521
def references(*args)
  options = args.extract_options!
  args.each do |ref_name|
    @base.add_reference(@table_name, ref_name, options)
  end
end
remove(*column_names)

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 480
def remove(*column_names)
  @base.remove_columns(@table_name, *column_names)
end
remove_belongs_to(*args)
Alias for: remove_references
remove_index(options = {})

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 494
def remove_index(options = {})
  @base.remove_index(@table_name, options)
end
remove_references(*args)

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)

See ActiveRecord::ConnectionAdapters::SchemaStatements#remove_reference

Also aliased as: remove_belongs_to
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 536
def remove_references(*args)
  options = args.extract_options!
  args.each do |ref_name|
    @base.remove_reference(@table_name, ref_name, options)
  end
end
remove_timestamps()

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 501
def remove_timestamps
  @base.remove_timestamps(@table_name)
end
rename(column_name, new_column_name)

Renames a column.

t.rename(:description, :name)
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 508
def rename(column_name, new_column_name)
  @base.rename_column(@table_name, column_name, new_column_name)
end
rename_index(index_name, new_index_name)

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 448
def rename_index(index_name, new_index_name)
  @base.rename_index(@table_name, index_name, new_index_name)
end
timestamps()

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 455
def timestamps
  @base.add_timestamps(@table_name)
end