|DROP FUNCTION(7)||PostgreSQL 15.4 Documentation||DROP FUNCTION(7)|
DROP_FUNCTION - remove a function
DROP FUNCTION [ IF EXISTS ] name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ] [, ...]
[ CASCADE | RESTRICT ]
DROP FUNCTION removes the definition of an existing function. To execute this command the user must be the owner of the function. The argument types to the function must be specified, since several different functions can exist with the same name and different argument lists.
This command removes the square root function:
DROP FUNCTION sqrt(integer);
Drop multiple functions in one command:
DROP FUNCTION sqrt(integer), sqrt(bigint);
If the function name is unique in its schema, it can be referred to without an argument list:
DROP FUNCTION update_employee_salaries;
Note that this is different from
DROP FUNCTION update_employee_salaries();
which refers to a function with zero arguments, whereas the first variant can refer to a function with any number of arguments, including zero, as long as the name is unique.
This command conforms to the SQL standard, with these PostgreSQL extensions: