php登录 session

Question

我的网页有一个登录系统。您创建用户名和密码，然后返回主页以使用正确的登录详细信息登录。我输入我的详细信息，它让我进入并出现一个警告框，上面写着“欢迎回来”。当我单击“确定”时，它会短暂显示该网页，但随后会直接返回登录页面。我已经开始 session ，因为注册页面工作正常。关于为什么登录页面这样做有什么想法吗？

代码如下:

if( empty( $_POST['client_username'] ) || empty( $_POST['client_password'] ) ) {
    die('You did not fill in a required field');
    }


    $qry = sprintf( "SELECT client_username, client_password FROM client WHERE client_username = '%s' LIMIT 1", mysql_real_escape_string( $_POST['client_username'] ) );
    $result = mysql_query( $qry );

    if( $result ) {
        if( mysql_num_rows( $result ) == 0 ) {
            die('That username does not exist in our database.');
        }
    }



    $info = mysql_fetch_assoc( $result );

    if( md5( $_POST['client_password'] ) != $info['client_password'] ) {
        die('Incorrect password, please try again.');
    }


    $client_id = mysql_query("SELECT* FROM client WHERE client_id = '$client_id'"); 

    $qry = sprintf( "UPDATE client SET client_last_access = NOW() WHERE client_username = '%s'", $info['client_username'] );
    if( !mysql_query( $qry ) ) {
        die('Error: ' . mysql_error() );
    } else {

        $_SESSION['client_username'] = $info['client_username'];
        $_SESSION['client_password'] = $info['client_password'];

        $_SESSION['client_id'] = $client_id;


        echo '<script>alert("Welcome Back");</script>';
        echo '<meta http-equiv="Refresh" content="0;URL=pv.php">';
    }

Answer 1

完全删除最后一行。