case statement doesn't go to else - sql

Question

I am wondering why the following query doesn't give 'N/A' when there are no rows for ENVIRON='Dev/Int'. It is returning null in the result of the query. I tried doing NVL(COUNT(*)) but that does't work either.
Any thoughts?
Thanks in advance.
SELECT G1.NAME,
(SELECT CASE
WHEN COUNT(*) > 0 AND ticket IS NOT NULL THEN 'Solved'
WHEN COUNT(*) > 0 AND ticket IS NULL THEN 'Done'
ELSE 'N/A'
END
FROM TABLE1
WHERE ENVIRON='Dev/Int' AND G1.NAME=NAME GROUP BY ENVIRON, ticket ) "Dev/Int"
FROM TABLE1 G1 group by G1.NAME

Answer 1

It doesn't give any rows because you are filtering them all out. The case is inside the query. When there are no rows to process, it returns NULL.
I think you just want conditional aggregation. The subqueries don't seem necessary:
SELECT G1.NAME,
(CASE WHEN SUM(CASE WHEN ENVIRON = 'Dev/Int' then 1 else 0 END) > 0 AND ticket IS NOT NULL
THEN 'Solved'
WHEN SUM(CASE WHEN ENVIRON = 'Dev/Int' then 1 else 0 END) > 0 AND ticket IS NULL
THEN 'Done'
ELSE 'N/A'
END) as "Dev/Int"
FROM TABLE1
group by G1.NAME;
EDIT:
Oops, the above left ticket out of the sum(). I think the logic you want has ticket in the sum() condition:
SELECT G1.NAME,
(CASE WHEN SUM(CASE WHEN ENVIRON = 'Dev/Int' AND ticket IS NOT NULL then 1 else 0 END) > 0
THEN 'Solved'
WHEN SUM(CASE WHEN ENVIRON = 'Dev/Int' AND ticket IS NULL then 1 else 0 END) > 0
THEN 'Done'
ELSE 'N/A'
END) as "Dev/Int"
FROM TABLE1
group by G1.NAME;
I'm surprised your original query worked at all and didn't get an error of the sort that subquery returned more than one row.