二种方式:
$url = "mysql:host=主机地址;dbname=库名";
$user = "用户名";
$pwd = "密码";
$conn = new PDO($url，$user，$pwd);
$conn->query("set names utf8");
$st = $conn->prepare("select语句");//指定
$st->execute();//执行
$rs = $st->fetchAll();
foreach($rs as $value)
{
echo $value["字段名|列序号"];
}
unset($rs);
unset($st);
unset($conn);
　　mysql增、删、改操作，insert|update|delete语句
　　一种方式:
$url = "mysql:host=主机地址;dbname=库名";
$user = "用户名";
$pwd = "密码";
$conn = new PDO($url，$user，$pwd);
$conn->query("set names utf8");
$row = $conn->exec("insert|update|delete语句");
unset($conn);
　　二种方式:
$url = "mysql:host=主机地址;dbname=库名";
$user = "用户名";
$pwd = "密码";
$conn = new PDO($url，$user，$pwd);
$conn->query("set names utf8");
$st = $conn->prepare("insert|update|delete语句"); //指定要执行的sql语句， 指定where Id=:a ，参数名:a
$st->bindParam(":名"，$变量); //bind绑定 paramter参数：为sql语句中的:a 绑定变量$id
$result = $st->execute(); //执行prepare所指定的sql语句
unset($st);
unset($conn);