Currently recommended to use either the MySQLI or PDO extensions. It is not recommended to use the old MySQLI extension for new development, as it was deprecated in PHP 5.5.0 and was removed in PHP 7.
| Features | MySQLI Extention | PDO |
| PHP version introduced | 5 | 5.1 |
| Development status | Active | Active |
| Database Support | Only MySQL | 10+ Databases |
| Recommended for new projects | Yes | Yes |
| OOP Interface | Yes | Yes |
| Procedural Interface | Yes | No |
| Persistent Connections | Yes | Yes |
| API supports Charsets | Yes | Yes |
| API supports server-side Prepared Statements | Yes | Yes |
| API supports client-side Prepared Statements | No | Yes |
| API supports Stored Procedures | Yes | Yes |
| API supports Multiple Statements | Yes | Yes |
| API supports Transactions | Yes | Yes |
| Transactions can be controlled with SQL | Yes | Yes |
| Supports all MySQL 5.1+ functionality | Yes | Mostly |