Drop a cast

The DROP CAST statement removes the definition for a cast from the database. The database server removes the class definition from the syscasts system catalog table. You must be the owner (the person who created the cast) or the DBA to drop its definition from the database.

Restriction: Do not drop the built-in casts, which user informix owns. The database server uses built-in casts for automatic conversions between built-in data types. Do not drop support functions for opaque data types that serve as casts if you still want to use the opaque data type in the database.

The following statements create and then remove casts between the mytype and DECIMAL data types:

CREATE CAST (decimal AS mytype WITH dec_to_mytype);
CREATE CAST (mytype AS decimal WITH mytype_to_decimal);
...
...
DROP CAST (decimal AS mytype);
DROP CAST (mytype AS decimal);

Dropping a cast has no effect on the function associated with the cast. The previous statements do not affect the dec_to_mytype or mytype_to_decimal functions. Use the DROP FUNCTION statement to remove a function from the database. For information about the syntax of DROP CAST and DROP FUNCTION, refer to the HCL OneDB™ Guide to SQL: Syntax.