Debug

In this article, we will focus on the mysqli_debug() function in PHP, which is used to enable or disable debugging output for MySQLi connections. We will provide you with an overview of the function, how it works, and examples of its use.

Introduction to the mysqli_debug() function

The mysqli_debug() function is a built-in function in PHP that is used to enable or disable debugging output for MySQLi connections. This function is useful when you need to debug MySQLi connections and see the SQL commands being executed by your code.

How to use the mysqli_debug() function

Using the mysqli_debug() function is very simple. You just need to call the function on a valid MySQLi object and pass in a boolean value to enable or disable debugging output. Here is an example:

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

mysqli_debug(true);

// 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 call the mysqli_debug() function with a value of true to enable debugging output for the connection. We can then execute queries using the connection and see the SQL commands being executed in the output.

Advanced usage

The mysqli_debug() function can also be used in more advanced scenarios. For example, you can use the function to enable debugging output for specific MySQLi objects. Here is an example:

<?php
$mysqli1 = mysqli_connect("localhost", "username", "password", "database1");
$mysqli2 = mysqli_connect("localhost", "username", "password", "database2");

mysqli_debug(true, $mysqli1);

// execute queries using the first connection

mysqli_debug(true, $mysqli2);

// execute queries using the second connection

mysqli_close($mysqli1);
mysqli_close($mysqli2);
?>

In this example, we create two MySQLi objects and connect to two different MySQL databases with a username and password. We then call the mysqli_debug() function with a value of true and the first MySQLi object to enable debugging output for the first connection. We can then execute queries using the first connection and see the SQL commands being executed in the output.

We then call the mysqli_debug() function again with a value of true and the second MySQLi object to enable debugging output for the second connection. We can then execute queries using the second connection and see the SQL commands being executed in the output.

Conclusion

In conclusion, the mysqli_debug() function is a useful tool for debugging MySQLi connections and seeing the SQL commands being executed in your code. 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.