Select column in main query from sub query (derived table) -

Question

Hi:
I have the following query - How do I select Tot_Atnd defined in the derived table
SELECT  count(distinct c.prgm_id) AS "Total Completed", h.Tot_Atnd
FROM  iplanrpt.vm_rpt_prgm  c
INNER JOIN
*(SELECT PRGM_ID, SUM(CASE WHEN ATTENDED_IND = 'Y' THEN 1 ELSE 0 END) AS "Tot_Atnd" FROM iPlanrpt.VM_RPT_PRGM_ATND GROUP BY PRGM_ID) h*
ON c.PRGM_ID = h.PRGM_ID
Thanks

Answer 1

Here's an example of what I think the CREATE TABLE and INSERT statements would look like for your data:
CREATE TABLE     vm_rpt_prgm
(     prgm_id     NUMBER
INSERT INTO     vm_rpt_prgm
VALUES     (1);
INSERT INTO     vm_rpt_prgm
VALUES     (2);
INSERT INTO     vm_rpt_prgm
VALUES     (3);
INSERT INTO     vm_rpt_prgm
VALUES     (1);
INSERT INTO     vm_rpt_prgm
VALUES     (1);
INSERT INTO     vm_rpt_prgm
VALUES     (3);
CREATE TABLE     vm_rpt_prgm_atnd
(     prgm_id     NUMBER
,     attended_ind     CHAR(1)
INSERT INTO     vm_prt_prgm_atnd
VALUES     (1, 'Y');
INSERT INTO     vm_prt_prgm_atnd
VALUES     (1, 'N');
INSERT INTO     vm_prt_prgm_atnd
VALUES     (2, 'Y');
INSERT INTO     vm_prt_prgm_atnd
VALUES     (2, 'Y');
INSERT INTO     vm_prt_prgm_atnd
VALUES     (2, 'N');
INSERT INTO     vm_prt_prgm_atnd
VALUES     (3, 'Y');
INSERT INTO     vm_prt_prgm_atnd
VALUES     (3, 'N');
INSERT INTO     vm_prt_prgm_atnd
VALUES     (3, 'N');But, I don't know your data. The sample data should be a simplified case of reality that represents (as best as possible) the real data set. For example, in vm_rpt_prgm, can the same prgm_id show up in multiple records? If not, the sample data I provided above is not representative of your data. Similar questions for vm_rpt_prgm_atnd: Can the same prgm_id show up in multiple records? Are the values of attended_ind 'Y' or 'N'? Can there be prgm_id's that exist in this table, but not the other? If not, again, my sample data is not representative of yours, so adjust it as needed and re-post it.
Here's some quick summary information on my sample data above:
There are 3 distinct values of prgm_id in vm_rpt_prgm.
There are 4 distinct values of prgm_id in vm_rpt_prgm_atnd.
There are 6 rows/records in vm_rpt_prgm.
There are 9 rows/records in vm_rpt_prgm_atnd.
The count of all 'Y's in vm_rpt_prgm_atnd is 5.
The count of all 'Y's in vm_rpt_prgm_atnd for only the prgm_id's in vm_rpt_prgm is 4.
So, which of these things (or other things) do you want to see in your result set?
You might say you want to see:
COUNT_OF_UNIQUE_PRGMS     TOTAL_ATND_YS
3                    4or...
PRGM_ID     TOTAL_ATND_YS
1          1
2          2
3          1
4          1Once you clearly specify what you want, I can probably help you