1DROP FUNCTION(7) PostgreSQL 16.1 Documentation DROP FUNCTION(7)
2
3
4
6 DROP_FUNCTION - remove a function
7
9 DROP FUNCTION [ IF EXISTS ] name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ] [, ...]
10 [ CASCADE | RESTRICT ]
11
13 DROP FUNCTION removes the definition of an existing function. To
14 execute this command the user must be the owner of the function. The
15 argument types to the function must be specified, since several
16 different functions can exist with the same name and different argument
17 lists.
18
20 IF EXISTS
21 Do not throw an error if the function does not exist. A notice is
22 issued in this case.
23
24 name
25 The name (optionally schema-qualified) of an existing function. If
26 no argument list is specified, the name must be unique in its
27 schema.
28
29 argmode
30 The mode of an argument: IN, OUT, INOUT, or VARIADIC. If omitted,
31 the default is IN. Note that DROP FUNCTION does not actually pay
32 any attention to OUT arguments, since only the input arguments are
33 needed to determine the function's identity. So it is sufficient to
34 list the IN, INOUT, and VARIADIC arguments.
35
36 argname
37 The name of an argument. Note that DROP FUNCTION does not actually
38 pay any attention to argument names, since only the argument data
39 types are needed to determine the function's identity.
40
41 argtype
42 The data type(s) of the function's arguments (optionally
43 schema-qualified), if any.
44
45 CASCADE
46 Automatically drop objects that depend on the function (such as
47 operators or triggers), and in turn all objects that depend on
48 those objects (see Section 5.14).
49
50 RESTRICT
51 Refuse to drop the function if any objects depend on it. This is
52 the default.
53
55 This command removes the square root function:
56
57 DROP FUNCTION sqrt(integer);
58
59 Drop multiple functions in one command:
60
61 DROP FUNCTION sqrt(integer), sqrt(bigint);
62
63 If the function name is unique in its schema, it can be referred to
64 without an argument list:
65
66 DROP FUNCTION update_employee_salaries;
67
68 Note that this is different from
69
70 DROP FUNCTION update_employee_salaries();
71
72 which refers to a function with zero arguments, whereas the first
73 variant can refer to a function with any number of arguments, including
74 zero, as long as the name is unique.
75
77 This command conforms to the SQL standard, with these PostgreSQL
78 extensions:
79
80 • The standard only allows one function to be dropped per command.
81
82 • The IF EXISTS option
83
84 • The ability to specify argument modes and names
85
87 CREATE FUNCTION (CREATE_FUNCTION(7)), ALTER FUNCTION
88 (ALTER_FUNCTION(7)), DROP PROCEDURE (DROP_PROCEDURE(7)), DROP ROUTINE
89 (DROP_ROUTINE(7))
90
91
92
93PostgreSQL 16.1 2023 DROP FUNCTION(7)