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Akshay Joshi
Akshay Joshi

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Using php7-mysql-shim to Address `mysql_*` Function Compatibility in PHP 7

#php #legacy #compatability #programming

Introduction

As of PHP 7, the mysql_* functions have been removed. Applications that still use these functions need to be updated or face compatibility issues. One solution is to use php7-mysql-shim, a library that provides a compatibility layer allowing the use of mysql_* functions in PHP 7 by mapping them to their mysqli_* equivalents.

What is php7-mysql-shim?

php7-mysql-shim is a PHP library designed to provide a drop-in replacement for the deprecated mysql_* functions. This allows legacy applications to run on PHP 7 and newer versions without requiring a complete rewrite of database interactions.

Benefits of Using php7-mysql-shim

  1. Seamless Transition: Allows legacy applications to run on modern PHP versions without extensive refactoring.
  2. Minimal Changes: Requires only the inclusion of the shim library, leaving existing codebase largely untouched.
  3. Cost-Effective: Saves time and resources that would otherwise be spent on rewriting code to use mysqli or PDO.

Installation

You can install php7-mysql-shim via Composer, a dependency manager for PHP.

Step-by-Step Installation

  1. Install Composer:
    If you don't already have Composer installed, you can install it by following the instructions at getcomposer.org.

  2. Require php7-mysql-shim:
    Navigate to your project directory and run the following command to add php7-mysql-shim to your project:

 composer require doozie-akshay/php7-mysql-shim
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  1. Include the Shim in Your Code: Add the following line at the beginning of your PHP scripts, ideally in a configuration file that is included in all your scripts: 
 require 'vendor/autoload.php';
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Example Usage

Original Code Using mysql_* Functions

Here’s an example of legacy code using mysql_* functions:

// config.php $db_host = 'localhost'; $db_user = 'root'; $db_password = ''; $db_name = 'test'; // Establish connection $connection = mysql_connect($db_host, $db_user, $db_password); if (!$connection) { die('Could not connect: ' . mysql_error()); } mysql_select_db($db_name, $connection);
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// check_user.php include_once('config.php'); $query = "SELECT * FROM users WHERE username = 'example_user'"; $result = mysql_query($query, $connection); if (!$result) { die('Query failed: ' . mysql_error()); } if (mysql_num_rows($result) > 0) { echo "User exists."; } else { echo "User does not exist."; } mysql_close($connection);
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Modified Code with php7-mysql-shim

After installing php7-mysql-shim, you only need to include the autoload file:

// config.php require 'vendor/autoload.php'; $db_host = 'localhost'; $db_user = 'root'; $db_password = ''; $db_name = 'test'; // Establish connection $connection = mysql_connect($db_host, $db_user, $db_password); if (!$connection) { die('Could not connect: ' . mysql_error()); } mysql_select_db($db_name, $connection);
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// check_user.php include_once('config.php'); $query = "SELECT * FROM users WHERE username = 'example_user'"; $result = mysql_query($query, $connection); if (!$result) { die('Query failed: ' . mysql_error()); } if (mysql_num_rows($result) > 0) { echo "User exists."; } else { echo "User does not exist."; } mysql_close($connection);
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Error Handling

php7-mysql-shim aims to provide full compatibility with the mysql_* functions, including error handling and other nuances. Ensure your existing error handling code remains effective without modification.

Conclusion

php7-mysql-shim provides a straightforward and effective solution for running legacy PHP applications that use mysql_* functions on PHP 7 and newer versions. By installing the shim and including it in your project, you can avoid extensive rewrites and ensure compatibility with modern PHP versions, allowing for a smooth transition and continued application functionality.

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