CALL — invoke a procedure
CALLname
( [argument
] [, ...] )
CALL executes a procedure.
If the procedure has any output parameters, then a result row will be returned, containing the values of those parameters.
name
The name (optionally schema-qualified) of the procedure.
argument
An argument expression for the procedure call.
Arguments can include parameter names, using the syntax
.
This works the same as in ordinary function calls; see
Section 4.3 for details.
name
=> value
Arguments must be supplied for all procedure parameters that lack
defaults, including OUT
parameters. However,
arguments matching OUT
parameters are not evaluated,
so it's customary to just write NULL
for them.
(Writing something else for an OUT
parameter
might cause compatibility problems with
future PostgreSQL™ versions.)
The user must have EXECUTE
privilege on the procedure in
order to be allowed to invoke it.
To call a function (not a procedure), use SELECT instead.
If CALL is executed in a transaction block, then the called procedure cannot execute transaction control statements. Transaction control statements are only allowed if CALL is executed in its own transaction.
PL/pgSQL handles output parameters in CALL commands differently; see Section 41.6.3.
CALL do_db_maintenance();
CALL 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.