'\" t
.\"     Title: DROP FUNCTION
.\"    Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets v1.75.2 <http://docbook.sf.net/>
.\"      Date: 2016
.\"    Manual: PostgreSQL 9.5.2 Documentation
.\"    Source: PostgreSQL 9.5.2
.\"  Language: English
.\"
.TH "DROP FUNCTION" "5sql" "2016" "PostgreSQL 9.5.2" "PostgreSQL 9.5.2 Documentation"
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.nh
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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)\&.
.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(5)), ALTER FUNCTION (\fBALTER_FUNCTION\fR(5))