错误未在登录表单中输出 [英] error not outputting in login form

问题描述

我的代码是

$query = "USE `davidedwardcakes`";
$result = mysql_query($query, $connect);
if(!isset($result)){echo 'no' .  mysql_error();}


$query = "SELECT * FROM `users` WHERE uname = '$uname'";
$result2 = mysql_query($query, $connect);
if(!$result2){echo 'wrong username or password' . mysql_error(); var_dump($result2);}
while($row = mysql_fetch_array($result2))
{echo $row['uname'] . $row['pass']; var_dump($result2);}

echo 'submited';

我正在尝试创建一个登录表单，但是每当我使用空白表单执行它时，我都没有得到任何错误输出.请帮忙.

I am trying to create a login form but i do not get any error output whenever i execute it with blank forms. Help please.

推荐答案

这是因为如果 $uname 为空字符串，查询仍然会成功运行.它只会有一个零行结果集.因此，您在何处执行此操作:

It is because the query will still run successfully if $uname is an empty string. It will just have a zero-row result set. As such, where you do this:

if(!$result2){echo 'wrong username or password' . mysql_error(); var_dump($result2);}

$result2 将有一个真值，您在条件中的代码将不会执行.

$result2 will have a truthy value and your code in the conditional will not execute.

您应该检查 mysql_num_rows() 以确定您是否有一个非空的结果集.

You should check mysql_num_rows() to determine if you have a non-empty result set.

顺便说一句，没有理由运行实际的mysql_query() 来选择要使用的数据库.mysql_select_db() 可用于此目的.

By the way, there is no reason to run an actual mysql_query() to select the DB to use. mysql_select_db() can be used for this purpose.

话虽如此，您应该使用 mysqli 或 PDO 而不是 mysql.

That being said, you should be using mysqli or PDO instead of mysql.

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