pdo exec()函数实现insert update操作

<?phptry{    header('Content-Type:text/html; charset=utf-8'); //网页utf8    $pdo = new PDO ('mysql:host=localhost;dbname=test', 'test', '123456'); //连接数据库    $pdo->query("set names utf8"); //数据库utf8    $pdo->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);    $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);    //exec() 执行一条sql语句并返回其受影响的记录的条数,没有受影响，返回值为0.    //exec() 对于select没有作用    //exec() 常用于对insert update 操作    $sql = "INSERT INTO test1 (id, name, password) VALUES (1, 'TEST', 'ABCD')";    $result = $pdo->exec($sql);     echo $result;      $sql = "UPDATE test1 SET name='sb' WHERE id=1";    $result = $pdo->exec($sql);     echo $result; }catch(PDOException $e){    echo $e->getMessage();}?>