1、PDO能够支持其它非MySQL的数据库,而MySQLi专门针对MySQL设计的
2、连接
//PDO
$pdo=newPDO("mysql:host=localhost;dbname=database",'username','password');
//mysqli,proceduralway
$mysqli=mysqli_connect('localhost','username','password','database');
//mysqli,objectorientedway
$m