In the query #2 from wich record do you expect result value for Descript would come from for each group? SQL Engine does not have this info and cannot proceed.

Table: mytable
Code Descript Qty
  1  One      110
  1  OneOne   120
  2  Two      210
  2  Two      220

-- #1
SELECT Code, SUM(Qty) FROM mytable GROUP BY Code
Result
Code Qty
  1  230
  2  430

-- #2
SELECT Code, Descript, SUM(Qty) FROM mytable GROUP BY Code
Result
Code Descript  Qty
  1  ?         230
  2  ?         430

>
>"....than SQL engine wouldn't know what record it should come from"
>
>Huh?? I don't get this.