'\" t
.\"     Title: CALL
.\"    Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 2024
.\"    Manual: PostgreSQL 16.2 Documentation
.\"    Source: PostgreSQL 16.2
.\"  Language: English
.\"
.TH "CALL" "7" "2024" "PostgreSQL 16.2" "PostgreSQL 16.2 Documentation"
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.SH "NAME"
CALL \- invoke a procedure
.SH "SYNOPSIS"
.sp
.nf
CALL \fIname\fR ( [ \fIargument\fR ] [, \&.\&.\&.] )
.fi
.SH "DESCRIPTION"
.PP
\fBCALL\fR
executes a procedure\&.
.PP
If the procedure has any output parameters, then a result row will be returned, containing the values of those parameters\&.
.SH "PARAMETERS"
.PP
\fIname\fR
.RS 4
The name (optionally schema\-qualified) of the procedure\&.
.RE
.PP
\fIargument\fR
.RS 4
An argument expression for the procedure call\&.
.sp
Arguments can include parameter names, using the syntax
\fIname\fR => \fIvalue\fR\&. This works the same as in ordinary function calls; see
Section\ \&4.3
for details\&.
.sp
Arguments must be supplied for all procedure parameters that lack defaults, including
OUT
parameters\&. However, arguments matching
OUT
parameters are not evaluated, so it\*(Aqs customary to just write
NULL
for them\&. (Writing something else for an
OUT
parameter might cause compatibility problems with future
PostgreSQL
versions\&.)
.RE
.SH "NOTES"
.PP
The user must have
EXECUTE
privilege on the procedure in order to be allowed to invoke it\&.
.PP
To call a function (not a procedure), use
\fBSELECT\fR
instead\&.
.PP
If
\fBCALL\fR
is executed in a transaction block, then the called procedure cannot execute transaction control statements\&. Transaction control statements are only allowed if
\fBCALL\fR
is executed in its own transaction\&.
.PP
PL/pgSQL
handles output parameters in
\fBCALL\fR
commands differently; see
Section\ \&43.6.3\&.
.SH "EXAMPLES"
.sp
.if n \{\
.RS 4
.\}
.nf
CALL do_db_maintenance();
.fi
.if n \{\
.RE
.\}
.SH "COMPATIBILITY"
.PP
\fBCALL\fR
conforms to the SQL standard, except for the handling of output parameters\&. The standard says that users should write variables to receive the values of output parameters\&.
.SH "SEE ALSO"
CREATE PROCEDURE (\fBCREATE_PROCEDURE\fR(7))