Question

I have a table of format

    id name flag
  ----------------
    11 Jack  1
    11 Jill  2
    23 Joe   1
    23 John  2
    23 Sam   1
    46 White 2
    46 Dan   2
    57 Dave  1

I am trying to return the table of format (based on the flag for particular id) like

    id name_1 name_2
   ------------------
    11 Jack   Jill
    23 Joe    John
    23 Sam    John
    46 NULL   White
    46 NULL   Dan
    57 Dave   NULL

I tried this query but it does not give the expected result.

select id,
case flag when 1 then name end as name_1,
case flag when 2 then name end as name_2
from temp;

Answer 1

You want a join, not a select case. Something like this, assuming null is possible in either column:

SELECT a.id, a.name fname, b.name lname from
(SELECT id, name FROM temp WHERE flag = 1) a 
full outer join 
(SELECT id, name FROM temp WHERE flag = 2) b on a.id = b.id

Not sure what you expect in this case though:

46 NULL   White
46 NULL   Dan