DROP FUNCTION
Synopsis
Use the DROP FUNCTION statement to remove a function from a database.
Syntax
Grammar
Diagramdrop_function ::= DROP FUNCTION [ IF EXISTS ]
{ subprogram_name ( [ subprogram_signature ] ) }
[ , ... ] [ CASCADE | RESTRICT ]
subprogram_signature ::= arg_decl [ , ... ]
arg_decl ::= [ formal_arg ] [ arg_mode ] arg_type
You must identify the to-be-dropped function by:
-
Its name and the schema where it lives. This can be done by using its fully qualified name or by using just its bare name and letting name resolution find it in the first schema on the search_path where it occurs. Notice that you don't need to (and cannot) mention the name of its owner.
-
Its signature. The subprogram_call_signature is sufficient; and this is typically used. You can use the full subprogram_signature. But you should realize that the formal_arg and arg_mode for each arg_decl carry no identifying information. (This is why it is not typically used when a function or procedure is to be altered or dropped.) This is explained in the section Subprogram overloading.
Semantics
-
An error will be thrown if the function does not exist unless
IF EXISTSis used. Then a notice is issued instead. -
RESTRICTis the default and it will not drop the function if any objects depend on it. -
CASCADEwill drop any objects that transitively depend on the function.
Examples
DROP FUNCTION IF EXISTS inc(i integer), mul(integer, integer) CASCADE;