Migrating from the deprecated mysql_* functions in PHP 5.6 to the PHP Data Objects (PDO) extension in PHP 7.4 can be a daunting task, but it is important to do so in order to improve the security and performance of your application. In this blog, we will walk through the process of migrating from mysql_* to PDO and discuss some of the key considerations and best practices to keep in mind.
Before beginning the migration process, it is important to plan and prepare for the move. This includes identifying which mysql_* functions are used in your application and determining the most efficient and cost-effective way to replace them with PDO. It’s also important to thoroughly test your application on a development or staging server to ensure that it is compatible with PDO.
One of the biggest benefits of using PDO is that it is a database-agnostic extension, which means that it can be used to connect to a variety of different databases, including MySQL, PostgreSQL, and SQLite. This can make it easier to switch between databases in the future if necessary.
Another benefit of using PDO is that it supports prepared statements, which can help to prevent SQL injection attacks. Prepared statements allow you to separate the data from the SQL query, which can help to prevent malicious data from being executed as part of the query.
To migrate from mysql_* to PDO, you will need to replace any instances of mysql_* functions with the equivalent PDO functions. This may involve updating the database connection and query code, as well as any error handling code.
It’s also important to keep in mind the security and compliance requirements during this migration process. PDO provides various security features such as prepared statements, which can help to prevent SQL injection attacks.
Once the migration is complete, it is important to thoroughly test your application again to ensure that everything is working as expected. This includes monitoring the performance of your application, troubleshooting any issues that may arise, and making any necessary adjustments to your PDO configuration.
Some major issues we faces post migrations are:
We migrated from mysql_* with PDO
- We implemented PDO in such a way that it can also handle read-replica in future Db::getPdoRead, Db::getPdoWrite, but there was a challenge in the beginning, team was making mistake to using it in right object which actually created problem for form data not being stored in database,
- Converting bigger SELECT with multiple tables joins and multiple parameters query to PDO
- Another issue we faced was after conversion sometime response got swapped index_value to key_value or voice-versa
- Other issue related to same we faced was we have to fetchAll() record but we use fetch() or voice-versa we created data mismatch
- We decided to replace mysql_real_escape_string() with addslashes() which created another issue on production while saving html contents.
Merging branches, lots of conflicts, if someone forgot to rebase or worked for weeks without taking updates . It took week to resolve conflicts.
In conclusion, migrating from the deprecated mysql_* functions in PHP 5.6 to the PHP Data Objects (PDO) extension in PHP 7.4 can be a complex process, but it is important to do so in order to improve the security and performance of your application. It’s important to plan and prepare for the move, replace any instances of mysql_* functions with the equivalent PDO functions, and keep in mind the security and compliance requirements during this migration process. It’s also important to thoroughly test your application after the migration to ensure that everything is working as expected.