Specific duplicate finding

[gausie]

I need to select all rows in my table that are duplicates. But the classification of being duplicates are if they have any other rows with the same "user_id" and "item_id". Even if the other columns are different, it is still a duplicate if those two are the duplicated anywhere.

 

Can someone help me with this query?

 

gausie

[Wildbug]

SELECT CONCAT(user_id,' & ',item_id) AS useritem_id,COUNT(*) AS num 
FROM table
GROUP BY useritem_id
HAVING num > 1;

 

Post table definition and an example case if you want more detail.