'\" t
.\"     Title: DROP FUNCTION
.\"    Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 2019
.\"    Manual: PostgreSQL 9.6.12 Documentation
.\"    Source: PostgreSQL 9.6.12
.\"  Language: English
.\"
.TH "DROP FUNCTION" "7" "2019" "PostgreSQL 9.6.12" "PostgreSQL 9.6.12 Documentation"
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.SH "NAME"
DROP_FUNCTION \- remove a function
.SH "SYNOPSIS"
.sp
.nf
DROP FUNCTION [ IF EXISTS ] \fIname\fR ( [ [ \fIargmode\fR ] [ \fIargname\fR ] \fIargtype\fR [, \&.\&.\&.] ] )
    [ CASCADE | RESTRICT ]
.fi
.SH "DESCRIPTION"
.PP
\fBDROP FUNCTION\fR
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\&.
.SH "PARAMETERS"
.PP
IF EXISTS
.RS 4
Do not throw an error if the function does not exist\&. A notice is issued in this case\&.
.RE
.PP
\fIname\fR
.RS 4
The name (optionally schema\-qualified) of an existing function\&.
.RE
.PP
\fIargmode\fR
.RS 4
The mode of an argument:
IN,
OUT,
INOUT, or
VARIADIC\&. If omitted, the default is
IN\&. Note that
\fBDROP FUNCTION\fR
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\&.
.RE
.PP
\fIargname\fR
.RS 4
The name of an argument\&. Note that
\fBDROP FUNCTION\fR
does not actually pay any attention to argument names, since only the argument data types are needed to determine the function\*(Aqs identity\&.
.RE
.PP
\fIargtype\fR
.RS 4
The data type(s) of the function\*(Aqs arguments (optionally schema\-qualified), if any\&.
.RE
.PP
CASCADE
.RS 4
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, \(lqDependency Tracking\(rq, in the documentation)\&.
.RE
.PP
RESTRICT
.RS 4
Refuse to drop the function if any objects depend on it\&. This is the default\&.
.RE
.SH "EXAMPLES"
.PP
This command removes the square root function:
.sp
.if n \{\
.RS 4
.\}
.nf
DROP FUNCTION sqrt(integer);
.fi
.if n \{\
.RE
.\}
.SH "COMPATIBILITY"
.PP
A
\fBDROP FUNCTION\fR
statement is defined in the SQL standard, but it is not compatible with this command\&.
.SH "SEE ALSO"
CREATE FUNCTION (\fBCREATE_FUNCTION\fR(7)), ALTER FUNCTION (\fBALTER_FUNCTION\fR(7))