accessing the return value of called procedure

[-]

this is one way of creating a stored procedure in mysql:

CREATE PROCEDURE some_procedure (IN value1, OUT value2)
BEGIN
SELECT ... INTO value2 FROM ....
END//


and if called from another procedure, i can access the variable this way:

CREATE PROCEDURE another_procedu re (....)
BEGIN
DECLARE count INT;
...
CALL some_procedure( ..., count);
IF (count ... ) THEN
END IF;
...
...
END//


there is another way of creating a stored procedure in mysql without
using a variable:

CREATE PROCEDURE some_procedure (IN value1)
BEGIN
SELECT ... FROM ....
END//


if i were to use this way, how can i access the return value?

CREATE PROCEDURE another_procedu re (....)
BEGIN
...
CALL some_procedure( ...); <==== how to access the value?
...
...
END//


i tried several ways:

1) SET count = CALL some_procedure( ...);
2) IF ((CALL some_procedure( ...)) ...) THEN

but both produce an error.

[Bill Karwin]

Re: accessing the return value of called procedure

- wrote:[color=blue]
> i tried several ways:
>
> 1) SET count = CALL some_procedure( ...);
> 2) IF ((CALL some_procedure( ...)) ...) THEN
>
> but both produce an error.[/color]

A procedure that returns a value instead of having an OUT parameter is
called a FUNCTION. This is created with the CREATE FUNCTION statement.
Functions are very similar to procedures, except that they cannot
reference any tables; that is, they can't perform queries.

Looking in the grammar source code for MySQL 5.0.2, there _appears_ to
be support for queries of the form:
SELECT * FROM PROCEDURE procname();
But I can't get it to work. It might be an unfinished feature. We are
using 5.0 alpha, after all.

Is it a problem to use a variable and fill it by passing it as an OUT
parameter to the procedure?

Regards,
Bill K.