PHP MySQLi MYSQLI_ASYNC - Asynchronous Queries

MYSQLI_ASYNC Constant

The MYSQLI_ASYNC constant is used as an optional parameter in the mysqli_query() function. It allows the query to be executed asynchronously, meaning that the PHP script does not wait for the results, but immediately proceeds with executing the next line of code.

EXAMPLE

<?php
$connection = mysqli_connect("localhost", "root", "", "mysqli_database");

if (!$connection) {
    die("Connection failed: " . mysqli_connect_error());
}

// Normal query (PHP waits)
mysqli_query($connection, "SELECT * FROM mysqli_table");

// Asynchronous query (PHP does NOT wait)
mysqli_query($connection, "SELECT * FROM mysqli_table", MYSQLI_ASYNC);

echo "The script continues to execute while the database is still working!";

mysqli_close($connection);
?>

RESULT

The result will be displayed here...

Practical use: This is extremely useful when you have long-running queries (e.g., generating reports) but still want to display the rest of the web page to the user as quickly as possible. The results of such a query are fetched later using the reap_async_query() method.

Prevents the PHP script from blocking while waiting for the database.

Allows parallel execution of multiple queries at the same time.

Requires using mysqli_poll() to check the status of the query.