MySql Distinct for same columns - mysql

Question

hi guys i have a data from sql like
UserID UserInfo ImageName Point
159 Ozan Işık 1575972330250.jpeg 32
558 Mert Malaveş 1578248740672.jpeg 36
68 Egemen Yılmaz 1573696212462.jpeg 82
558 Mert Malaveş 1578248740678.jpeg 36
Here is my sql
SELECT DISTINCT Users.UserID,Users.UserInfo,BestPracticeParticipant.ImageName ,BestPracticeParticipant.Point
FROM BestPracticeParticipant
JOIN Users on Users.UserID=BestPracticeParticipant.UserID
WHERE BestPracticeParticipant.BestPracticeID=1
But i need to data like this
UserID UserInfo ImageName Point
159 Ozan Işık 1575972330250.jpeg 32
558 Mert Malaveş 1578248740672.jpeg 36
68 Egemen Yılmaz 1573696212462.jpeg 82
i need same UserID rows doesnt duplicate but i cant group by because of the other veriables from my sql.
Thank you.

Answer 1

If you want a random matching row, you can use row_number():
SELECT u.*
FROM (SELECT u.UserID, u.UserInfo, bpp.ImageName, bpp.Point,
ROW_NUMBER() OVER (PARTITION BY u.UserID ORDER BY rand()) as seqnum
FROM BestPracticeParticipant bpp JOIN
Users u
ON u.UserID = bpp.UserID
WHERE bpp.BestPracticeID = 1
) u
WHERE seqnum = 1;
Note: You can control which row you get by modifying the ROW_NUMBER().
EDIT: The above works on MySQL 8+. If you have an older version, then a unique id in the result set can be used to do what you want.
For instance, if ImageName is unique (for a given user):
SELECT u.UserID, u.UserInfo, bpp.ImageName, bpp.Point
FROM useres u JOIN
BestPracticeParticipant bpp
ON u.UserID = bpp.UserID
WHERE bpp.BestPracticeID = 1 AND
bpp.ImageName = (SELECT MAX(bpp2.ImageName)
FROM BestPracticeParticipant bpp2
WHERE bpp2.UserID = bpp.UserID AND
bpp2.BestPracticeID = 1
);

Answer 2

It seems your MySQL version doesn't support window functions. So from your sample data, You may try below query -
SELECT DISTINCT U.UserID,U.UserInfo,BPP.ImageName,BPP.Point
FROM (SELECT UserID, MIN(ImageName), Point
FROM BestPracticeParticipant
GROUP BY UserID, Point) BPP
JOIN Users U on U.UserID=BPP.UserID
WHERE BPP.BestPracticeID=1