从表WHERE UID = x AND CAT = y中删除

Question

I have a very simple table - 3 columns ID | UID | CAT

I am trying to run a mysql delete to remove the rows where both UID= something AND CAT= something. But it doesn't work. How do I do this?

$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 need to be escaped

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

another hint use mysql_real_escape_string or another form of checking user input

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

Answer 3

Do you have an active database connection? If not, you'll need to create one before calling mysql_query() .

Other than that, you may be forgetting single quotes in the query:

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

Should be:

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

Assuming CAT is not a numeric column.