Let's say this is your database:
   A    B           C 
  157  szept-01   3000 
  157  okt-01     -312
I tried this: (ofc, i get a not a group by warning, because C isn't grouped by) But i would like to get the value of C in my query, how could i solve it?
    Select A, MIN(B), C
    FROM DB
    GROUP BY A;
When i use this (I get every value of C for every B, but i ONLY want value C for the minimal B)
    Select A, MIN(B), C
    FROM DB
    GROUP BY A, C;
This is my purpose:
    A    B          C
   157  szept-01   3000
EDIT: I dont see it duplicate, the other is not solved perfectly imho. (There are tons of updates, and i dont see the exact answer)
