PHP MySQLi mysqli_insert_id() - Last Generated ID

mysqli_insert_id()

The mysqli_insert_id() function returns the ID generated by the AUTO_INCREMENT mechanism in the last query.

EXAMPLE

<?php
$server = "localhost";
$username = "root";
$password = "";
$database = "mysqli_database";

$connection = mysqli_connect($server, $username, $password, $database);

if (mysqli_connect_errno()) {
    echo "Connection failed: " . mysqli_connect_error();
    exit();
}

// Insert a new piece of fruit and vegetable into our table
mysqli_query($connection, "INSERT INTO mysqli_table (fruit, vegetable, date) VALUES ('Pear', 'Lettuce', '2026-06-14 13:00:00')");

// Retrieve the ID of the last inserted record
// NOTE: Since the table_id column is set to AUTO_INCREMENT, the database automatically assigns the 
// next number. With the mysqli_insert_id() function, we can instantly capture this number (e.g., to 
// redirect a user in an online store directly to the details of their new order).
echo "New record has ID: " . mysqli_insert_id($connection);

mysqli_close($connection);
?>

RESULT

The result will be displayed here...

Practical use: When you insert a new record into a table, this function immediately returns the unique number (ID) that the database assigned to this record. Look at the example below:

It returns an integer representing the last AUTO_INCREMENT key.

If the last query did not generate a new ID, the function returns 0.

Very useful in relational databases for linking tables.