从 MySQL 中选择数据不相同的行

Question

So i have a chat system and a topbar with notifications What i want to do is load the last message from the last X persons the user has chatted So i dont want to spam the notifications with X number of messages from the same person but i want to load the very LAST message from X number of persons

So here is my problem (example): Imagine if one person sent the user 8 messages and i limit the message query to 8 results. The query will return 8 messages from the same person but i've made a PHP filter that will echo only 1 message from one person. So basically this will only echo 1 message from 1 person but wont echo any other messages from any other person because ive limited the result query to 8 and this user already spammed 8 messages

This is my PHP filter (but i want to do this in SQL)

foreach ($sideMess as $smes) {
    if (!isset($showedList[$smes['id']])) { 
        echo '<div class="mes_wrap" id="ppl_', $smes['id'] ,'">
            <img src="', $smes['avatar'] ,'">
            <h4>', $smes['firstname'] ,' ', $smes['lastname'] ,'</h4>
            </div>';

        $showedList[$smes['id']] = true;
        $cS ++;
    }
}

Answer 1

As per your specification, it seems that you want list of last message from multiple users, ie, user-wise last message.

select * from
(select * from
messages
order by user_id,message_time desc) temp
group by user_id;

Answer 2

Okay, its solved! I used GROUP BY sender_id before ORDER BY Thanks for your help!