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Asked: 2026-06-13T08:55:00+00:00

I have a table: messages with this structure: `ID` // auto increment `SenderUserID` //

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I have a table: messages with this structure:

`ID`   //  auto increment
`SenderUserID`   // foreign key: `ID` from `User` table
`ReceiverUserID`   // foreign key: `ID` from `User` table
`Message`   
`DateCreated`   // timestamp

I need to get distinct ReceiverUserIDs from table by this conditions:

  1. Sender user should have conversations with receiver users.
  2. Selected distinct ReceiverUserID should give us last DateCreated message.

So in the results, I’ll have user last conversations ordered by creation date DESC.

When I distinct in select query, mysql return a first record, but I need maximum DateCreated for selected `ReceiverUserID to get last message in top of results.

SELECT DISTINCT `m`.`ReceiverUserID` AS `ID` FROM `messages` `m`
WHERE (`m`.`SenderUserID` = :UserID OR `m`.`ReceiverUserID` = :UserID) 
ORDER BY `m`.`DateCreated` DESC

//:UserID means LogedInUserID

It is good to know It will be exactly like facebook messages board.

ID, SenderUserID, ReceiverUserID, Message,  DateCreated
1, 12, 11, 'Hi admin', 2012-10-24 11:07:00
2, 11, 12, 'Hi guy',  2012-10-24 11:08:00
3, 11, 13, 'Hello dear customer',  2012-10-24 11:12:00
4, 11, 13, 'Are you there?',  2012-10-24 11:13:00
5, 13, 11, 'Hiiii',  2012-10-24 11:14:00  // last conversation betwen 11 & 13

Current logedin user id: 11

SELECT `m`.`ReceiverUserID` AS `ID`, MAX(`m`.`DateCreated`) as `lastmsg` 
FROM `messages` `m` WHERE (`m`.`SenderUserID` = 11 OR `m`.`ReceiverUserID` = 11) 
GROUP BY `m`.`ReceiverUserID`

We have problem in this section:
It is not return our last conversation between 11 and 13 when receiver user answered the sender message, It will be not seen in results

Results:

ID, lastmsg
12, 2012-10-24 11:08:00
13, 2012-10-24 11:13:00  // Should be: 13, 2012-10-24 11:14:00
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1 Answer

  1. Editorial Team

    As I mentioned you have to do the same with SenderUserID…

    SELECT `ID`, MAX(`lastmsg`) FROM 
(   SELECT `m`.`ReceiverUserID` AS `ID`, MAX(`m`.`DateCreated`) as `lastmsg` FROM `messages` `m`
    WHERE `m`.`SenderUserID` = :UserID
    GROUP BY `m`.`ReceiverUserID`
    UNION
    SELECT `m`.`SenderUserID` AS `ID`, MAX(`m`.`DateCreated`) as `lastmsg` FROM `messages` `m`
    WHERE `m`.`ReceiverUserID` = :UserID
    GROUP BY `m`.`SenderUserID`
) as table2 GROUP BY `ID` ORDER BY `lastmsg`
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