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 Title: DROP FUNCTION
 Author: The PostgreSQL Global Development Group
 Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
 Date: 2021
 Manual: PostgreSQL 10.19 Documentation
 Source: PostgreSQL 10.19
 Language: English

 "DROP FUNCTION" "7" "2021" "PostgreSQL 10.19" "PostgreSQL 10.19 Documentation"
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 "NAME"
DROP_FUNCTION - remove a function

 "SYNOPSIS"
DROP FUNCTION [ IF EXISTS ] name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ] [, ...]
 [ CASCADE | RESTRICT ]



 "DESCRIPTION"

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.

 "PARAMETERS"

IF EXISTS


Do not throw an error if the function does not exist. A notice is issued in this case.




name


The name (optionally schema-qualified) of an existing function. If no argument list is specified, the name must be unique in its schema.




argmode


The mode of an argument:
IN,
OUT,
INOUT, or
VARIADIC. If omitted, the default is
IN. Note that
DROP FUNCTION
does not actually pay any attention to
OUT
arguments, since only the input arguments are needed to determine the function\*(Aqs identity. So it is sufficient to list the
IN,
INOUT, and
VARIADIC
arguments.




argname


The name of an argument. Note that
DROP FUNCTION
does not actually pay any attention to argument names, since only the argument data types are needed to determine the function\*(Aqs identity.




argtype


The data type(s) of the function\*(Aqs arguments (optionally schema-qualified), if any.




CASCADE


Automatically drop objects that depend on the function (such as operators or triggers), and in turn all objects that depend on those objects (see
Section 5.13).




RESTRICT


Refuse to drop the function if any objects depend on it. This is the default.



 "EXAMPLES"

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.

 "COMPATIBILITY"

This command conforms to the SQL standard, with these
PostgreSQL
extensions:


\h'-04'\(bu\h'+03'\c
.\}

 \(bu 2.3
.\}
The standard only allows one function to be dropped per command.




\h'-04'\(bu\h'+03'\c
.\}

 \(bu 2.3
.\}
The
IF EXISTS
option




\h'-04'\(bu\h'+03'\c
.\}

 \(bu 2.3
.\}
The ability to specify argument modes and names



 "SEE ALSO"
CREATE FUNCTION (CREATE_FUNCTION(7)), ALTER FUNCTION (ALTER_FUNCTION(7))