Summary: in this tutorial, you will learn how to develop stored procedures that return multiple values.sql
MySQL stored function returns only one value. To develop stored programs that return multiple values, you need to use stored procedures with INOUT or OUT parameters.app
If you are not familiar with INOUT or OUT parameters, check it out the stored procedure’s parameters tutorial for the detailed information.ide
Stored procedures that return multiple values example
Let’s take a look at the orders table in the sample database.oop
The following stored procedure accepts customer number and returns the total number of orders that were shipped, canceled, resolved, and disputed.post
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DELIMITER $$
CREATE PROCEDURE get_order_by_cust(
IN cust_no INT,
OUT shipped INT,
OUT canceled INT,
OUT resolved INT,
OUT disputed INT)
BEGIN
-- shipped
SELECT
count(*) INTO shipped
FROM
orders
WHERE
customerNumber = cust_no
AND status = 'Shipped';
-- canceled
SELECT
count(*) INTO canceled
FROM
orders
WHERE
customerNumber = cust_no
AND status = 'Canceled';
-- resolved
SELECT
count(*) INTO resolved
FROM
orders
WHERE
customerNumber = cust_no
AND status = 'Resolved';
-- disputed
SELECT
count(*) INTO disputed
FROM
orders
WHERE
customerNumber = cust_no
AND status = 'Disputed';
END
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In addition to the IN parameter, the stored procedure takes four additional OUT parameters: shipped, canceled, resolved, and disputed. Inside the stored procedure, you use a SELECT statement with the COUNT function to get the corresponding total of orders based on the order’s status and assign it to the respective parameter.fetch
To use the get_order_by_cust stored procedure, you pass customer number and four user-defined variables to get the out values.this
After executing the stored procedure, you use the SELECT statement to output the variable values.spa
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CALL get_order_by_cust(141,@shipped,@canceled,@resolved,@disputed);
SELECT @shipped,@canceled,@resolved,@disputed;
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Calling stored procedures that return multiple values from PHP
The following code snippet shows you how to call the stored procedure that returns multiple values from PHP.
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<?php
/**
* Call stored procedure that return multiple values
* @param $customerNumber
*/
function call_sp($customerNumber)
{
try {
$pdo = new PDO("mysql:host=localhost;dbname=classicmodels", 'root', '');
// execute the stored procedure
$sql = 'CALL get_order_by_cust(:no,@shipped,@canceled,@resolved,@disputed)';
$stmt = $pdo->prepare($sql);
$stmt->bindParam(':no', $customerNumber, PDO::PARAM_INT);
$stmt->execute();
$stmt->closeCursor();
// execute the second query to get values from OUT parameter
$r = $pdo->query("SELECT @shipped,@canceled,@resolved,@disputed")
->fetch(PDO::FETCH_ASSOC);
if ($r) {
printf('Shipped: %d, Canceled: %d, Resolved: %d, Disputed: %d',
$r['@shipped'],
$r['@canceled'],
$r['@resolved'],
$r['@disputed']);
}
} catch (PDOException $pe) {
die("Error occurred:" . $pe->getMessage());
}
}
call_sp(141);
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The user-defined variables, which are preceded by the @ sign, are associated with the database connection, therefore, they are available for access between the calls.
In this tutorial, we have shown you how to develop a stored procedure that returns multiple values and how to call it from PHP.