Connect_errno

In this article, we will focus on the mysqli_connect_errno() function in PHP, which is used to get the last MySQLi connection error code. We will provide you with an overview of the function, how it works, and examples of its use.

Introduction to the mysqli_connect_errno() function

The mysqli_connect_errno() function is a built-in function in PHP that is used to get the last MySQLi connection error code. This function is useful when you need to debug MySQLi connection errors and determine the cause of the error.

How to use the mysqli_connect_errno() function

Using the mysqli_connect_errno() function is very simple. You just need to call the function on a valid MySQLi object. Here is an example:

<?php
$mysqli = mysqli_connect("localhost", "username", "password", "database");

if (mysqli_connect_errno()) {
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
    exit();
}

// execute queries using the connection

mysqli_close($mysqli);
?>

In this example, we call the mysqli_connect() function to connect to a MySQL database with a username and password. We then use the mysqli_connect_errno() function to check if there was an error in the connection. If there was an error, we output the error message using the mysqli_connect_error() function and exit the script. Otherwise, we can execute queries using the connection.

Advanced usage

The mysqli_connect_errno() function can also be used in more advanced scenarios. For example, you can use the function to get the error code and error message for a specific connection. Here is an example:

<?php
$mysqli = new mysqli("localhost", "username", "password", "database");

if ($mysqli->connect_errno) {
    echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;
    exit();
}

// execute queries using the connection

$mysqli->close();
?>

In this example, we create a new MySQLi object and connect to a MySQL database with a username and password. We then use the connect_errno property of the MySQLi object to get the error code for the connection. We can then use the connect_error property to get the error message for the connection. If there was an error, we output the error message and exit the script. Otherwise, we can execute queries using the connection.

Conclusion

In conclusion, the mysqli_connect_errno() function is a useful tool for debugging MySQLi connection errors in PHP. By understanding how to use the function and its advanced usage scenarios, you can take advantage of this feature to create powerful and flexible MySQLi queries in your PHP scripts.