PHP MySQL: Call MySQL Stored Procedures
Summary: in this tutorial, you will learn how to call MySQL stored procedures using PHP PDO. We will show you how to call stored procedures that return a result set and stored procedures that accept input/output parameters.
Calling stored procedures that return a result set
The steps of calling a MySQL stored procedure that returns a result set using PHP PDO are similar to querying data from MySQL database table using the SELECT statement. Instead of sending a SELECT statement to the MySQL database, you send a stored procedure call statement.
First, create a stored procedure named GetCustomers() in the sample database for the demonstration. The GetCustomers() stored procedure retrieves the name and credit limit of customers from the customers table.
The following GetCustomers() stored procedure illustrates the logic:
DELIMITER $$
CREATE PROCEDURE GetCustomers()
BEGIN
SELECT customerName, creditlimit
FROM customers;
END$$Second, create a new PHP file named phpmysqlstoredprocedure1.php with the following code:
<!DOCTYPE html>
<html>
<head>
<title>PHP MySQL Stored Procedure Demo 1</title>
<link rel="stylesheet" href="css/table.css" type="text/css" />
</head>
<body>
<?php
require_once 'dbconfig.php';
try {
$pdo = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);
// execute the stored procedure
$sql = 'CALL GetCustomers()';
// call the stored procedure
$q = $pdo->query($sql);
$q->setFetchMode(PDO::FETCH_ASSOC);
} catch (PDOException $e) {
die("Error occurred:" . $e->getMessage());
}
?>
<table>
<tr>
<th>Customer Name</th>
<th>Credit Limit</th>
</tr>
<?php while ($r = $q->fetch()): ?>
<tr>
<td><?php echo $r['customerName'] ?></td>
<td><?php echo '$' . number_format($r['creditlimit'], 2) ?>
</td>
</tr>
<?php endwhile; ?>
</table>
</body>
</html>Everything is straightforward except the SQL query:
CALL GetCustomers();We send the statement that calls the GetCustomers() stored procedure to MySQL. And we execute the statement to get a result set.
Third, test the script in the web browser to see how it works.
You can download the script via the following link:
Download PHP MySQL Stored Procedure Source Code
Calling stored procedures with an OUT parameter
It is a little bit tricky to call a stored procedure with the OUT parameter. We will use the GetCustomerLevel() a stored procedure that accepts a customer number as an input parameter and returns the customer level based on the credit limit.
Check the MySQL IF statement tutorial for detailed information on the GetCustomerLevel() stored procedure.
DELIMITER $$
CREATE PROCEDURE GetCustomerLevel(
in p_customerNumber int(11),
out p_customerLevel varchar(10))
BEGIN
DECLARE creditlim double;
SELECT creditlimit INTO creditlim
FROM customers
WHERE customerNumber = p_customerNumber;
IF creditlim > 50000 THEN
SET p_customerLevel = 'PLATINUM';
ELSEIF (creditlim <= 50000 AND creditlim >= 10000) THEN
SET p_customerLevel = 'GOLD';
ELSEIF creditlim < 10000 THEN
SET p_customerLevel = 'SILVER';
END IF;
END$$In MySQL, we can call the GetCustomerLevel() the stored procedure is as follows:
CALL GetCustomerLevel(103,@level);
SELECT @level AS level;In PHP, we have to emulate those statements:
- First, we need to execute the
GetCustomerLevel()stored procedure. - Second, to get the customer level, we need to query it from the variable
@level. It is important that we must call the methodcloseCursor()of thePDOStatementthe object in order to execute the next SQL statement.
Let’s take a look at how the logic is implemented in the following PHP script:
<?php
require_once 'dbconfig.php';
/**
* Get customer level
* @param int $customerNumber
* @return string
*/
function getCustomerLevel(int $customerNumber) {
try {
$pdo = new PDO("mysql:host=$host;dbname=$dbname", $username, $password);
// calling stored procedure command
$sql = 'CALL GetCustomerLevel(:id,@level)';
// prepare for execution of the stored procedure
$stmt = $pdo->prepare($sql);
// pass value to the command
$stmt->bindParam(':id', $customerNumber, PDO::PARAM_INT);
// execute the stored procedure
$stmt->execute();
$stmt->closeCursor();
// execute the second query to get customer's level
$row = $pdo->query("SELECT @level AS level")->fetch(PDO::FETCH_ASSOC);
if ($row) {
return $row !== false ? $row['level'] : null;
}
} catch (PDOException $e) {
die("Error occurred:" . $e->getMessage());
}
return null;
}
$customerNo = 103;
echo sprintf('Customer #%d is %s', $customerNo, getCustomerLevel($customerNo));If you test the script in the web browser, you will see the following screenshot:
You can download the script via the following link:
Download PHP MySQL Stored Procedure with the OUT Parameter Source Code
In this tutorial, you have learned how to call MySQL stored procedures using PHP PDO.
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