MySQL SELECT unique column where other column is max

Question

I have table like this

  id     |     serial_num     |      version     | .....
  1      |         1          |          1       | .....
  2      |         2         


        

Answer 1

Selecting id for a group by query is useless. You should only select the column you are using in group by and other columns that are being applied aggregate functions.

Hope this works for you.

SELECT id, 
       serial_num, 
       Max(`version`) `version`
FROM   tbl1 
GROUP  BY serial_num