Introduction

PHP developers, especially those with a few years of experience, might recognize the mysql_* functions, such as mysql_connect(), mysql_query(), etc. These were once the standard for interfacing with MySQL databases. However, their use has been discouraged for several reasons, pushing developers towards alternatives like MySQLi and PDO (PHP Data Objects).

Historical Context

The mysql_* functions were introduced in PHP for interacting with MySQL databases. Over time, these functions grew to be outdated and were ultimately deprecated in PHP 5.5.0 and removed in PHP 7.0. This article explores why you should avoid using these functions and opt for more modern solutions.

Reasons Not to Use mysql_* Functions

1. Deprecated and Removed

The most pressing reason to stop using mysql_* functions is that they have been deprecated and removed from PHP. This means:

• No updates or security patches are available.
• They pose a security risk by potentially opening doors for SQL injection.

2. Lack of Security Features

The mysql_* functions lack support for modern security practices, most notably:

• Prepared Statements: mysql_* functions do not support prepared statements, which help prevent SQL injection attacks by isolating SQL logic from data input.

3. Poor Error Handling

Error handling was rudimentary with mysql_*, making debugging and maintaining code more difficult. Developers have limited options to manage what happens when errors occur.

4. No Support for New Features

Modern MySQL features, such as stored procedures, transactions, and multi-statements, are not supported by mysql_* functions. If you want to utilize these features in your application, you must use MySQLi or PDO.

5. Lack of Object-Oriented Interface

While mysql_* functions are procedural, MySQLi and PDO offer object-oriented approaches, providing more flexibility and neatness in the code structure.

6. Reduced Performance

In some cases, you'll find better performance utilizing MySQLi or PDO due to support for optimized options like persistent connections.

Comparing Alternatives: MySQLi vs PDO

MySQLi (MySQL Improved)

• Pros:
  • Better than mysql_* with support for prepared statements.
  • Offers both procedural and object-oriented interfaces.
  • Supports MySQL-specific features.
• Cons:
  • MySQLi is specific to MySQL.

PDO (PHP Data Objects)

• Pros:
  • Supports multiple database types, not just MySQL.
  • Provides a clean interface for prepared statements and transactions.
• Cons:
  • Does not support MySQL-specific functions.

Example Comparison

Here is a simple comparison of how MySQLi and PDO handle a query with prepared statements:

MySQLi Example

1$mysqli = new mysqli("localhost", "user", "password", "database");
2$stmt = $mysqli->prepare("SELECT * FROM users WHERE username = ?");
3$stmt->bind_param("s", $username);
4$stmt->execute();
5$result = $stmt->get_result();

PDO Example

1$pdo = new PDO("mysql:host=localhost;dbname=database", "user", "password");
2$stmt = $pdo->prepare("SELECT * FROM users WHERE username = ?");
3$stmt->execute([$username]);
4$result = $stmt->fetchAll();

Summary Table

Conclusion

While mysql_* functions were once staple components of PHP development, their deprecation serves as a reminder to stay informed of evolving best practices. Choosing MySQLi or PDO not only distanced your application from potential security threats but also leverages improved features of modern MySQL interacting functions. Always aim to write secure, maintainable, and future-proof code by selecting the right tools and libraries.