Oracle 9i sql question

Question

I have a single column query pulling say 3 or more rows.
select col1 from tab1
1
2
3
How to rewrite the query so I get results as one single row with results as "1,2,3 "
Thanks.
Edited by: rajugopalli on Sep 9, 2011 10:12 AM

Answer 1

Hi,
That's called String Aggregation , and the following page shows several ways to do it:
http://www.oracle-base.com/articles/10g/StringAggregationTechniques.php
Which one should youuse? That depends on your specific requirements (e.g., whether or not order is important).
Here's one way that will work in Oracle 9:
WITH     got_r_num     AS
     SELECT     col1
     ,     ROW_NUMBER () OVER (ORDER BY col1)     AS r_num
     FROM     tab1
SELECT     MAX ( SUBSTR ( SYS_CONNECT_BY_PATH (col1, ',')
                  , 2
         )     AS col1_list
FROM    got_r_num
START WITH     r_num     = 1
CONNECT BY     r_num     = PRIOR r_num + 1
;This puts ithe values into the list in ascending order.
There are better ways starting in Oracle 10, though this will still work, of course.
Edited by: Frank Kulash on Sep 9, 2011 1:21 PM