path: root/doc/src/sgml/man7/DROP_PROCEDURE.7

'\" t
.\"     Title: DROP PROCEDURE
.\"    Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 2024
.\"    Manual: PostgreSQL 16.3 Documentation
.\"    Source: PostgreSQL 16.3
.\"  Language: English
.\"
.TH "DROP PROCEDURE" "7" "2024" "PostgreSQL 16.3" "PostgreSQL 16.3 Documentation"
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.SH "NAME"
DROP_PROCEDURE \- remove a procedure
.SH "SYNOPSIS"
.sp
.nf
DROP PROCEDURE [ IF EXISTS ] \fIname\fR [ ( [ [ \fIargmode\fR ] [ \fIargname\fR ] \fIargtype\fR [, \&.\&.\&.] ] ) ] [, \&.\&.\&.]
    [ CASCADE | RESTRICT ]
.fi
.SH "DESCRIPTION"
.PP
\fBDROP PROCEDURE\fR
removes the definition of one or more existing procedures\&. To execute this command the user must be the owner of the procedure(s)\&. The argument types to the procedure(s) usually must be specified, since several different procedures can exist with the same name and different argument lists\&.
.SH "PARAMETERS"
.PP
IF EXISTS
.RS 4
Do not throw an error if the procedure does not exist\&. A notice is issued in this case\&.
.RE
.PP
\fIname\fR
.RS 4
The name (optionally schema\-qualified) of an existing procedure\&.
.RE
.PP
\fIargmode\fR
.RS 4
The mode of an argument:
IN,
OUT,
INOUT, or
VARIADIC\&. If omitted, the default is
IN
(but see below)\&.
.RE
.PP
\fIargname\fR
.RS 4
The name of an argument\&. Note that
\fBDROP PROCEDURE\fR
does not actually pay any attention to argument names, since only the argument data types are used to determine the procedure\*(Aqs identity\&.
.RE
.PP
\fIargtype\fR
.RS 4
The data type(s) of the procedure\*(Aqs arguments (optionally schema\-qualified), if any\&. See below for details\&.
.RE
.PP
CASCADE
.RS 4
Automatically drop objects that depend on the procedure, and in turn all objects that depend on those objects (see
Section\ \&5.14)\&.
.RE
.PP
RESTRICT
.RS 4
Refuse to drop the procedure if any objects depend on it\&. This is the default\&.
.RE
.SH "NOTES"
.PP
If there is only one procedure of the given name, the argument list can be omitted\&. Omit the parentheses too in this case\&.
.PP
In
PostgreSQL, it\*(Aqs sufficient to list the input (including
INOUT) arguments, because no two routines of the same name are allowed to share the same input\-argument list\&. Moreover, the
\fBDROP\fR
command will not actually check that you wrote the types of
OUT
arguments correctly; so any arguments that are explicitly marked
OUT
are just noise\&. But writing them is recommendable for consistency with the corresponding
\fBCREATE\fR
command\&.
.PP
For compatibility with the SQL standard, it is also allowed to write all the argument data types (including those of
OUT
arguments) without any
\fIargmode\fR
markers\&. When this is done, the types of the procedure\*(Aqs
OUT
argument(s)
\fIwill\fR
be verified against the command\&. This provision creates an ambiguity, in that when the argument list contains no
\fIargmode\fR
markers, it\*(Aqs unclear which rule is intended\&. The
\fBDROP\fR
command will attempt the lookup both ways, and will throw an error if two different procedures are found\&. To avoid the risk of such ambiguity, it\*(Aqs recommendable to write
IN
markers explicitly rather than letting them be defaulted, thus forcing the traditional
PostgreSQL
interpretation to be used\&.
.PP
The lookup rules just explained are also used by other commands that act on existing procedures, such as
\fBALTER PROCEDURE\fR
and
\fBCOMMENT ON PROCEDURE\fR\&.
.SH "EXAMPLES"
.PP
If there is only one procedure
do_db_maintenance, this command is sufficient to drop it:
.sp
.if n \{\
.RS 4
.\}
.nf
DROP PROCEDURE do_db_maintenance;
.fi
.if n \{\
.RE
.\}
.PP
Given this procedure definition:
.sp
.if n \{\
.RS 4
.\}
.nf
CREATE PROCEDURE do_db_maintenance(IN target_schema text, OUT results text) \&.\&.\&.
.fi
.if n \{\
.RE
.\}
.sp
any one of these commands would work to drop it:
.sp
.if n \{\
.RS 4
.\}
.nf
DROP PROCEDURE do_db_maintenance(IN target_schema text, OUT results text);
DROP PROCEDURE do_db_maintenance(IN text, OUT text);
DROP PROCEDURE do_db_maintenance(IN text);
DROP PROCEDURE do_db_maintenance(text);
DROP PROCEDURE do_db_maintenance(text, text);  \-\- potentially ambiguous
.fi
.if n \{\
.RE
.\}
.sp
However, the last example would be ambiguous if there is also, say,
.sp
.if n \{\
.RS 4
.\}
.nf
CREATE PROCEDURE do_db_maintenance(IN target_schema text, IN options text) \&.\&.\&.
.fi
.if n \{\
.RE
.\}
.SH "COMPATIBILITY"
.PP
This command conforms to the SQL standard, with these
PostgreSQL
extensions:
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
The standard only allows one procedure to be dropped per command\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
The
IF EXISTS
option is an extension\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
The ability to specify argument modes and names is an extension, and the lookup rules differ when modes are given\&.
.RE
.SH "SEE ALSO"
CREATE PROCEDURE (\fBCREATE_PROCEDURE\fR(7)), ALTER PROCEDURE (\fBALTER_PROCEDURE\fR(7)), DROP FUNCTION (\fBDROP_FUNCTION\fR(7)), DROP ROUTINE (\fBDROP_ROUTINE\fR(7))