PostgreSQL 9.4 Документация
Пред	Выше		След

DROP CAST

Name

DROP CAST -- remove a cast

DROP CAST [ IF EXISTS ] (source_type AS target_type) [ CASCADE | RESTRICT ]

DROP CAST removes a previously defined cast.

To be able to drop a cast, you must own the source or the target data type. These are the same privileges that are required to create a cast.

IF EXISTS: Do not throw an error if the cast does not exist. A notice is issued in this case.
source_type: The name of the source data type of the cast.
target_type: The name of the target data type of the cast.
CASCADE RESTRICT: These key words do not have any effect, since there are no dependencies on casts.

To drop the cast from type text to type int:

DROP CAST (text AS int);

The DROP CAST command conforms to the SQL standard.

Пред	Начало	След
DROP AGGREGATE	Выше	DROP COLLATION