How to Retrieve the Last Inserted ID in PHP and MySQL

In this article, we will guide you through the steps of retrieving the last inserted ID in PHP and MySQL. When inserting data into a database, it is often necessary to retrieve the ID of the last inserted record. This is useful for a variety of purposes, such as linking related records in the database.

Prerequisites

Before we start, there are a few prerequisites that you should have in place:

• A web server with PHP installed
• A MySQL database
• Access to the PHPMyAdmin interface or similar database management tool

Establishing a Connection

The first step in retrieving the last inserted ID is to establish a connection to the database. This is done by using the mysqli_connect() function, which requires the following parameters:

• The name of the database server
• The username used to access the database
• The password for the database user
• The name of the database to connect to

Here is an example of how to establish a connection to a database:

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

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

if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}
echo "Connected successfully";
?>

Writing the SQL Statement

Once a connection to the database has been established, the next step is to write the SQL statement that will be used to insert the data into the database.

Here is an example of a SQL statement that inserts data into a database table:

INSERT INTO table_name (column1, column2, column3)
VALUES ('value1', 'value2', 'value3');

Executing the SQL Statement

Once the SQL statement has been written, the next step is to execute it. This is done by using the mysqli_query() function, which requires the following parameters:

• The connection to the database
• The SQL statement to be executed

Here is an example of how to execute the SQL statement:

<?php
$sql = "INSERT INTO table_name (column1, column2, column3)
VALUES ('value1', 'value2', 'value3')";

if (mysqli_query($conn, $sql)) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . mysqli_error($conn);
}
?>

Retrieving the Last Inserted ID

Once the data has been inserted into the database, the next step is to retrieve the ID of the last inserted record. This is done by using the mysqli_insert_id() function, which requires the following parameter:

• The connection to the database

Here is an example of how to retrieve the last inserted ID:

<?php
$last_id = mysqli_insert_id($conn);
echo "Last inserted ID is: " . $last_id;
?>

Closing the Connection

Once the last inserted ID has been retrieved, it is important to close the connection to thedatabase to avoid any security risks. This is done by using the mysqli_close() function, which requires the following parameter:

• The connection to the database

Here is an example of how to close the connection to the database:

<?php
mysqli_close($conn);
?>

Conclusion

In this article, we have shown you how to retrieve the last inserted ID in PHP and MySQL. By following these steps, you should be able to retrieve the ID of the last inserted record in your database. It is important to note that the exact steps may vary depending on the specific database management system that you are using, so be sure to consult the documentation for your system for more information.