Question

I have a table as below:

table1

col1    col2    col3
1        A       1
2        B       1
3        A       2
4        D       2
5        X       3
6        G       3

Now can I get the result like below from above table. THe col2 in the below resultset is based on the col3 in table1 above. In above table1 col2, A and B have same id value in COL3 (i.e 1) so in the result set we just separate it in new columns and so on. A and D have same id COL3 (i.e 2) and X and G have same id in COL3 (i.e 3) in above table1. ANyone can write a sql query to get the following result.

   col1   col2    
     A      B 
     A      D
     X      G

Answer 1

If you are on SQL Server 2005 or later:

WITH ranked AS (
  SELECT
    *,
    rn = ROW_NUMBER() OVER (PARTITION BY col3 ORDER BY col2)
  FROM table1
)
SELECT
  col1 = r1.col2,
  col2 = r2.col2
FROM ranked r1
  INNER JOIN ranked r2 ON r1.col3 = r2.col3
WHERE r1.rn = 1
  AND r2.rn = 2