How to retrieve two columns data in A,B format in Oracle

Question

I have two columns in oracle database

+---------+---------+
| Column1 | Column2 |
+---------+---------+
| A       | 1       |
| A       | 2       |
+--------         


        

Answer 1

On my oracle version 10 it do the job:

SELECT column1, wm_concat( column2)
  FROM table_name
 GROUP BY column1