Question

如果查询失败，我需要返回false ...我把它放在哪里......

function asas($username,$password){
    $qry = "SELECT * 
            FROM members 
            WHERE login='$username' AND passwd='".md5($password)."'";

    $result = mysql_query($qry);

    while($row = mysql_fetch_array($result)) 
    {
            return(array($row['userlevel'], $row['email']));
    }

    //return 'Invalid username / password ';
}

Answer 1

mysql_query 失败时返回false，就像mysql_fetch_array一样。所以你的代码应该如下：

function asas($username,$password) {
   $qry="SELECT * 
         FROM members 
         WHERE login='$username' AND passwd='".md5($password)."'";

   $result=mysql_query($qry);

   // if fail is intended the failure of the mysql connection
   if (!$result) return false;

   $row = mysql_fetch_array($result);

   if ($row) return array($row['userlevel'],$row['email']);

   // if fail is intended as username and password didn't match
   return false; 
}

您会注意到该函数有几个退出点。如果是家庭作业，你应该把它们集中在一个。

Answer 2

if(mysql_num_rows($result)===0)
    return false;
else
    while(...

我是如何看待它的。您甚至可以在while循环后直接使用return false;。尝试一下，看看它有效。

Answer 3

function asas($username,$password){
    $qry="SELECT * FROM members 
          WHERE login='$username' AND passwd='".md5($password)."'";
    $result=mysql_query($qry);

    if (!$result) {
        /* Something went wrong with the query */
        return false;
    }
    while($row = mysql_fetch_array($result)) 
    {
        return(array($row['userlevel'],$row['email']));
    }

    /* if the query found any rows then the code above would or returned it */
    return false;
    //return 'Invalid username / password ';
}

在PHP中失败的条件下返回值

3 个答案: