从表WHERE UID = x AND CAT = y中删除

Question

我有一个非常简单的表-3列ID | UID | 猫

我试图运行mysql删除以删除其中UID =某物和CAT =某物的行。 但这是行不通的。 我该怎么做呢？

$uid = $_POST['UID'];
$cat = $_POST['CAT'];

mysql_query("DELETE FROM Categories WHERE UID = ".$uid." AND CAT=".$cat."");

Answer 1

尝试这个：

mysql_query("DELETE FROM Categories WHERE UID = $uid AND CAT='$cat'");

Answer 2

$uid = $_POST['UID'];
$cat = $_POST['CAT'];

mysql_query("DELETE FROM Categories WHERE UID = ".$uid." AND CAT=".$cat."");

VARCHAR需要转义

mysql_query("DELETE FROM Categories WHERE UID = ".$uid." AND CAT='".$cat."'");

另一个提示使用mysql_real_escape_string或另一种检查用户输入的形式

$uid = mysql_real_escape_string($_POST['UID']);
$cat = mysql_real_escape_string($_POST['CAT']);

Answer 3

您有活动的数据库连接吗？ 如果不是，则需要在调用mysql_query()之前创建一个。

除此之外，您可能会忘记查询中的单引号：

mysql_query("DELETE FROM Categories WHERE UID = ".$uid." AND CAT=".$cat."");

应该：

mysql_query("DELETE FROM Categories WHERE UID = ".$uid." AND CAT='".$cat."'");

假设CAT不是数字列。