SQL query using Group by and Aggregate function

Question

Hi All,
I need your help in writing an SQL query to achieve the following.
Scenario:
I have table with 3 Columns. There are 3 possible values for col3 - Success, Failure & Error.
Now I need a query which can give me the summary counts for distinct values of col3 for each GROUP BY of col1 and col2 values. When there are no values for col3 then it should return ZERO count.
Example Data:
Col1 Col2 Col3
abc 01 success
abc 02 success
abc 01 success
abc 01 Failure
abc 01 Error
abc 02 Failure
abc 03 Error
xyz 07 Failure
Required Output:
c1 c2 s_cnt F_cnt E_cnt (Heading)
abc 01 2 1 1
abc 02 1 1 0
abc 03 0 0 1
xyz 07 0 1 0
s_cnt = Success count; F_cnt = Failure count; E_cnt = Error count
Please note that the output should have 5 columns with col1, col2, group by (col1,col2)count(success), group by (col1,col2)count(failure), group by (col1,col2)count(error)
and where ever there are NO ROWS then it should return ZERO.
Thanks in advance.
Regards,
Shiva

Answer 1

Hi,
user13015050 wrote:
Thanks TTT. Unfortunately I cannot use this solution because I have huge data for this.T's solution is basically the same as mine. The first 23 lines just simulates your table. Since you actually have a table, you would start with T's line 24:
SELECT col1 c1, col2 c2, SUM(decode(col3, 'success', 1, 0)) s_cnt, ...
user13015050 wrote:Thanks a lot Frank. It helped me out. I just did some changes to this as below and have no issues.
SELECT     col1
,     col2
,     COUNT ( CASE
          WHEN col3 = 'SUCCESS'
          THEN 1
          END
     )          AS s_cnt
,     COUNT ( CASE
          WHEN col3 = 'FAILED'
          THEN 1
          END
     )          AS f_cnt
,     COUNT ( CASE
          WHEN col3 = 'ERROR'
          THEN 1
          END
     )          AS e_cnt
FROM     t1
WHERE c2 in ('PURCHASE','REFUND')
and c4 between to_date('20091031000000','YYYYMMDDHH24MISS') AND to_date('20100131235959','YYYYMMDDHH24MISS')
GROUP BY c1, c2
ORDER BY c1, c2;
Please let me know if you see any issues in this query.It's very hard to read.
This site normally compresses spaces. Whenever you post formatted text (such as queries or results) on this site, type these 6 characters:
\(small letters only, inside curly brackets) before and after each section of formatted text, to preserve spacing.
Also, post exactly what you're using.  The code above is SELECTing col1 and col2, but there's no mention of either in the GROUP BY clause, so I don't believe it's really what you're using.
Other than that, I don't see anything wrong or suspicious in the query.