Which is better, MySQL or MySQLi? And why? Which should I use?
I mean better not just in terms of performance, but any other relevant feature.
If you have a look at MySQL Improved Extension Overview, it should tell you everything you need to know about the differences between the two.
The main useful features are:
There is a manual page dedicated to help choosing between mysql, mysqli and PDO at
The PHP team recommends mysqli or PDO_MySQL for new development:
It is recommended to use either the mysqli or PDO_MySQL extensions. It is not recommended to use the old mysql extension for new development. A detailed feature comparison matrix is provided below. The overall performance of all three extensions is considered to be about the same. Although the performance of the extension contributes only a fraction of the total run time of a PHP web request. Often, the impact is as low as 0.1%.
The page also has a feature matrix comparing the extension APIs. The main differences between mysqli and mysql API are as follows:
mysqli mysql
Development Status Active Maintenance only
Lifecycle Active Long Term Deprecation Announced*
Recommended Yes No
OOP API Yes No
Asynchronous Queries Yes No
Server-Side Prep. Statements Yes No
Stored Procedures Yes No
Multiple Statements Yes No
Transactions Yes No
MySQL 5.1+ functionality Yes No
* http://news.php.net/php.internals/53799
There is an additional feature matrix comparing the libraries (new mysqlnd versus libmysql) at
and a very thorough blog article at