MySQL查询表现得很奇怪 [英] MySQL query acting weird

问题描述

我有:

mysql_connect($host,$username,$password);
@mysql_select_db("db") or die("Error: Cannot select database");
$query = "select password from users where name = '".$_POST['login-userid']."'";
$result = mysql_query($query);

if ($result == false) {
    echo "Invalid username or password";
} else {
    if (mysql_result($result,0) == hash('sha256', $_POST['login-password'])) {
         echo "Logging in...";
    }
}

出于某种原因，我不断收到 mysql_result 行的错误，即使它不应该被执行(当用户名不存在时，即 $result 评估为 false).

For some reason I keep getting an error for the mysql_result line, even when it shouldn't be executed (when the username doesn't exist, ie $result evaluates to false).

推荐答案

mysql_query 只会在出现错误时返回 false.在这种情况下没有错误，只有 0 行.

mysql_query will only return false if there is an error. In this case there is no error, there are just 0 rows.

您需要使用 mysql_num_rows 来获取返回的行数.

You need to use mysql_num_rows to get the number of rows returned.

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