在登录页面中使用FOUND_ROWS

时间:2012-07-14 22:08:52

标签: php mysql sql sql-calc-found-rows

我正在尝试设置一个用户登录页面(基本培训,因为我学习php),但页面无法正常工作,因为我认为我的部件有问题我计算行数 (我检查我的user_table数据库中输入的登录名和密码与已输入的登录名和密码匹配的行数= 1)。

我在PDO中,我不想使用being deprecated mysql_num_rows,或者至少建议不要使用它。相反,我想使用Found_rows

这是我的login_page.php:

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="fr" lang="fr">
<head>
    <title>LOGIN PAGE</title>
    <meta http-equiv="content-type" content="text/html; charset=utf-8" />
</head>
<body>
<h1>Connect to your account</h1>
    <form method="post" action="login_verify.php">
        <input type="text" name="inputed_username" size="35" maxlength="30" required="required" value="Enter your login" /><br/><br/>
        <input type="password" name="inputed_password" size="35" maxlength="30" required="required" value="Enter your password" /><br/><br/>
        <input type="submit" name="submit "value="Connect me !" />         
    </form>
</body>
 </html>

然后这是php文件,我在这个login_verify.php文件中检查输入的{login,password}是否正确:

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="fr" lang="fr">
<head>
    <title>login process check-up</title>
    <meta http-equiv="content-type" content="text/html; charset=utf-8" />
</head>
<body>
<?php
    if (isset($_POST['submit']))//if the button submit has not been clicked on
    {
        try
        {
            //database connection          
            $dbhost     = "localhost";
            $dbname     = "test";
            $dbuser     = "root";
            $dbpass     = "";

            $pdo_options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION;
            $bdd = new PDO("mysql:host=$dbhost;dbname=$dbname; charset=UTF8",$dbuser,$dbpass,$pdo_options);
            $bdd -> query('SET NAMES utf8'); 

            //the database is checked to see if there is a match for the couple {user,password}

            $user = $_POST['inputed_username'];
            $password = $_POST['inputed_password'];
            //preparaiton and execution of the request
            $req = $bdd->prepare('SELECT * from user_table WHERE login= :login && password= :password LIMIT 1');
            $req->execute(array(
            'login' => $user,
            'password' => $password));
            $foundrows = $req->query("SELECT FOUND_ROWS()")->fetchColumn();//the number of rows are counted

            //we check if there is a match for the login-password
            if ($foundrows == 1)//if we find one that matches
            {
                session_start();
                $_SESSION['username'] = $req['login'];
                $_SESSION['fname'] = $req['first_name'];
                $_SESSION['lname'] = $req['last_name'];
                $_SESSION['logged'] = TRUE;
                header("Location: first_page.php");
                exit();
            }
            else //if we don't find any match
            {
                header("Location: login_page.php");
                exit;
            }
        }
        catch (Exception $e)
        {
            die('Erreur: '.$e->getMessage());
        }

    }
    else //if the submit button has  not been clicked on
    {
        header ("Location: login_page.php");
        exit;
    }
?>

如果你们中任何人知道问题所在,那就太棒了。

我认为它来自于滥用found_rows。这是我第一次使用它,所以我觉得我有些不好,但我不知道它是什么。

1 个答案:

答案 0 :(得分:1)

FOUND_ROWS()仅在您在select查询中具有SQL_CALC_FOUND_ROWS选项的select查询之后使用它时才有效,并且只有在它是LIMIT查询时才真正有用。 FOUND_ROWS()是如果不是limit子句则返回WOULD的行数。

SELECT SQL_CALC_FOUND_ROWS ... WHERE ... LIMIT 10
SELECT FOUND_ROWS()

对于非LIMITed查询,请改用mysql_num_rows()

据推测,您的数据库设置为login是主要/唯一关键字段,因此您的查询最多只返回一行,因此限制毫无意义。