Hide Order By Column From SELECT Without Using Temp Table

Question

Well, I know we can hide order by column from select statement by using temp tables . Just wondering how to do the same without using temp tables ?

As the db I'm working is so huge, adding temp tables impact query performance a lot.

My Query is something like following:

SELECT DISTINCT
  Col1,
  MAX(Col2),
  MAX(Col3),
  Col4
FROM 
  Table1
Group By
  Col4,
  Col1
Order By
  Col4

Now all i want is to get rid of Col4 from Output without using temp tables. Can't even do that using inner query. Thanks.

Answer 1

If your Col4 is computed/derived and it has to be in original select, you may simple make an outer query:

SELECT G.Col1, G.C2, G.C3 from
(SELECT DISTINCT
  Col1,
  MAX(Col2) AS C2,
  MAX(Col3) AS C3,
  Col4
FROM 
  Table1
Group By
  Col4,
  Col1
Order By
  Col4) AS G

Answer 2

Typically, the sort column(s) does not need to be included in the select list. This is a common operation - no explicit temp table required.

select color
from fruit
order by weight

http://sqlfiddle.com/#!6/ba09d/3