Unable to get OUT parameter in PHP

[Galen Mayfield]

All,

Hi. I've read through this forum, a few web sites, and a couple books, so I'm sure I'm probably just overlooking something. In that case, let me apologize in advance for my question. However, I've hit a bit of snag and am hoping you can help me out. I'm an experienced ASP programmer, but new to PHP and MySQL.

I have a stored procedure that, when I call it from the MySQL query browser, works just fine. However, when I call it from PHP, I get nothing back. This leads me to believe that I'm calling it from PHP in the wrong way. The Code:

SP:
-----------

DELIMITER $$

DROP PROCEDURE IF EXISTS `litrunner`.`authenticateUser` $$
CREATE DEFINER=`xx@xx` PROCEDURE `authenticateUser`(IN useremail VARCHAR(100), IN userpassword VARCHAR(40), OUT AUTHENTICATIONCODE INT)
BEGIN

DECLARE numMatches INT DEFAULT 0;


SET numMatches = (SELECT COUNT(*) FROM vwUsers WHERE email = useremail AND password = userpassword);

CASE numMatches


-- AUTHENTICATION CODES

-- 0 = NO MATCH
-- 1 = 1 MATCH FOUND
-- 2 = MULTIPLE MATCHES FOUND
-- 3 = UNDEFINED


WHEN numMatches<0 THEN
SET AUTHENTICATIONCODE = 3;
WHEN 0 THEN
SET AUTHENTICATIONCODE = 0;
WHEN 1 THEN
SET AUTHENTICATIONCODE = 1;
WHEN numMatches>1 THEN
SET AUTHENTICATIONCODE = 2;
ELSE
SET AUTHENTICATIONCODE = 3;

END CASE;

END $$

DELIMITER ;
----

Here ends the SP code. When I call this from the query browser like so:

call authenticateUser('[e-mail]', 'anotherLiteral', @AUTHENTICATIONCODE);
SELECT @AUTHENTICATIONCODE;

I get back the appropriate AUTHENTICATIONCODE.


PHP snippet:
-----
$useremail = $_POST['email'];
$userpassword = $_POST['password'];

$db_conn = new mysqli($host, $dbusername, $dbpassword, $db);

if (mysqli_connect_errno()) {
echo 'Login Failed. Your username and/or password are incorrect.';
exit();
}

$authCode = "";

$authenticationResultSet = $db_conn->multi_query("call authenticateUser($useremail, $userpassword, @AUTHENTICATIONCODE);SELECT @AUTHENTICATIONCODE");
echo "dudedafdfs:";
if ($authenticationResultSet) {
echo "dudes:";
$results = 0;
do {

if ($result = $db_conn->store_result()) {

while($row = $result->fetch->fetch_row()) {
foreach($row as $cell) {
$authCode = $cell;
echo "dude: ".$cell."<BR><BR>";
}
}
$result->close();
}
} while($db_conn->next_result());
}
----
Here ends the PHP snippet. The condition if ($authenticationResultSet) is not coming out true, so I'm guessing there's something wrong w/ this statement:

$authenticationResultSet = $db_conn->multi_query("call authenticateUser($useremail, $userpassword, @AUTHENTICATIONCODE);SELECT @AUTHENTICATIONCODE");

Any guidance you can provide will be much appreciated.

Thanks in advance.