获取组中具有最高ID的值-MySQL

Question

I'm trying to get the row with the highest ID from a group, rather than the lowest. I heard you have to do that JOIN trick, but it's confusing and I can't get my head around it.

My code so far is this:

$userp0l=//userID
$where=//forumID
    SELECT * 
    FROM `noti` 
    WHERE forum='$where' 
    AND user <>  '$userp0l'
    GROUP BY user 
    ORDER BY `id` 
    DESC

It works, however it is showing the first entry in the group, rather than the latest. Anyone know how I can rewrite this?

I just said I'd post all of my code, but looking at it, there's not really much else. I run this statement:

 $elist = mysql_query("SELECT * FROM `noti` WHERE forum='$where' AND user <>  '$userp0l' GROUP BY user ORDER BY `id` DESC") or die(mysql_error());

It gets the information from the database. The information is grouped so I do not capture a user twice when I go to renter data into the table:

if(mysql_num_rows($elist) > 0){
while($elist_result = mysql_fetch_array($elist)){
  $shownotir=$elist_result['shownoti']; 
  $userr=$elist_result['user'];
  $forumr=$elist_result['forum'];
    if($shownotir=="n"){
            $pps="INSERT INTO `noti`(`user`, `forum`, `shownoti`, `forumn`, `madeby`) VALUES ('$userr', '$where', '0', '$forumn', '$uu')";
        mysql_query($pps) or die(mysql_error());
    }
    else {
        $pps="INSERT INTO `noti`(`user`, `forum`, `shownoti`, `forumn`, `madeby`) VALUES ('$userr', '$where', '1', '$forumn', '$uu')";
        mysql_query($pps) or die(mysql_error());
    }
     }
    }

I need to find if the most recent entry of shownoti is a 1 or a 0 . The trouble is, when grouping, it takes the first entry rather than the latest. So if the most recent entry has a shownoti value of 0 , but the first entry value has a 1 , it will always show 1 as it is seeing the first entry. I want to order the groups backwards, basically.

Answer 1

Use DISTINCT

SELECT DISTINCT `user`, `shownoti`
FROM `noti` 
WHERE forum = '97' 
AND user <> '9797'
GROUP BY `user`, `shownoti`
ORDER BY `id` DESC

You have to remember that 4 (from 420) is greater than 1 (from 1350) so your sorting may have to be a little different. I have created an example here .