The error message "Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future" appears in environments where PHP code is used with functions for working with the MySQL database using the old mysql extension. This message informs developers that the mysql_connect() function, which is used to establish a connection with a MySQL database, is deprecated and will be removed in future versions of PHP.

What Does "Deprecated" Mean?

In programming, the term "Deprecated" is used for functions, methods, or entire libraries that are marked as outdated and their use is not recommended. These designations serve as a warning to developers that they should move to newer and safer alternatives, as these deprecated components may be completely removed in future versions.

Why Was the mysql Extension Marked as Deprecated?

The mysql extension was marked as deprecated for several reasons. One of the main reasons is that it does not support advanced features of modern database systems, such as prepared statements, which enhance security by more effectively preventing SQL injection attacks. Another reason is the better performance and flexibility of newer interfaces, such as PDO (PHP Data Objects) and mysqli (MySQL Improved).

How to Solve the Problem

To solve the problem, it is recommended to switch to a more modern interface for working with databases, specifically PDO or mysqli. Both interfaces provide better security, performance, and compatibility with new PHP versions.

Transition to mysqli

1. Establishing Connection: Instead of mysql_connect(), use mysqli_connect(), which requires specifying the server, username, password, and database name.

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

2. Executing Queries: Instead of mysql_query(), use mysqli_query(), which requires the connection object as the first argument.

   $result = mysqli_query($conn, "SELECT * FROM table");
   

Transition to PDO

1. Establishing Connection: PDO allows connection to various types of databases using DSN (Data Source Name). The connection is established as follows:

   $conn = new PDO("mysql:host=server;dbname=database", "username", "password");
   

2. Executing Queries: With PDO, queries are executed using prepared statements, which increases security.

   $stmt = $conn->prepare("SELECT * FROM table");
   $stmt->execute();
   $result = $stmt->fetchAll();
   

Switching from the deprecated mysql extension to mysqli or PDO not only resolves the deprecation warning issue but also provides developers with access to safer and more efficient methods for working with databases. It is important to update existing code in time to ensure its compatibility with future PHP versions and the overall security of applications.