Conditional count when case = 1, DB2 - sql

Question

I'm currently trying to figure out the best way to do a conditional count as an alias in DB2 for Iseries. The below values represent job statuses where a job can be created, completed and cancelled so any one job will possibly have multiple status codes attached to it.
However, for my final value, I'm trying to get a count of jobs that only have the created status so that I can show how many are still open jobs. Basically looking for cases where the count for the created case = 1, but the below fails at the '='
SELECT
COUNT(CASE A1.JOB WHEN = 'CREATED' THEN 1 END) AS CREATED,
COUNT(CASE A1.JOB WHEN = 'CANCELLED' THEN 1 END) AS CANCELLED,
COUNT(CASE WHEN A1.JOB 'CREATED' = 1 then 1 END) AS OPEN
FROM SCHEMA.TABLE A1;
sample data and results:
Job ID | Status_code
-------------------------
123 'CREATED'
123 'COMPLETED'
521 'CREATED'
521 'CANCELLED'
645 'CREATED'
Results:
JOB | CREATED | CANCELLED | OPEN
-------------------------------------------
123 1 0 0
521 1 1 0
645 1 0 1

Answer 1

Assuming that the only "close" status is 'CANCELLED', you can use not exists like this:
select count(*)
from schema.table t
where t.status_code = 'CREATED' and
not exists (select 1
from schema.table t2
where t2.job = t.job and
t2.status_code in ('CANCELLED', 'COMPLETED', 'DELETED')
);
If you want multiple counts, then filtering like this does not work. So aggregate by job first:
select sum(is_created) as num_created,
sum(is_cancelled) as num_cancelled,
sum(is_created * (1 - is_cancelled) * (1 - is_completed) * (1 - is_deleted)) as open
from (select job,
max(case when status_code = 'CREATED' then 1 else 0 end) as is_created,
max(case when status_code = 'CANCELLED' then 1 else 0 end) as is_cancelled,
max(case when status_code = 'COMPLETED' then 1 else 0 end) as is_completed,
max(case when status_code = 'DELETED' then 1 else 0 end) as is_deleted
from t
group by job
) j

Answer 2

The following returns the result you need:
WITH TAB (Job_ID, JOB) AS
(
VALUES
(123, 'CREATED')
, (123, 'COMPLETED')
, (521, 'CREATED')
, (521, 'CANCELLED')
, (645, 'CREATED')
)
SELECT
Job_ID
, COUNT(CASE A1.JOB WHEN 'CREATED' THEN 1 END) AS CREATED
, COUNT(CASE A1.JOB WHEN 'CANCELLED' THEN 1 END) AS CANCELLED
, CASE
WHEN NULLIF(COUNT(1), 0) = COUNT(CASE A1.JOB WHEN 'CREATED' then 1 END)
THEN 1
ELSE 0
END AS OPEN
FROM TAB A1
GROUP BY JOB_ID;

Answer 3

With conditional aggregation:
SELECT
JobID,
MAX(CASE Status_code WHEN 'CREATED' THEN 1 ELSE 0 END) AS CREATED,
MAX(CASE Status_code WHEN 'CANCELLED' THEN 1 ELSE 0 END) AS CANCELLED,
MIN(CASE WHEN Status_code <> 'CREATED' THEN 0 ELSE 1 END) AS OPEN
FROM tablename
GROUP BY JobID
See the demo.
Results:
> JobID | CREATED | CANCELLED | OPEN
> ----: | ------: | --------: | ---:
> 123 | 1 | 0 | 0
> 521 | 1 | 1 | 0
> 645 | 1 | 0 | 1

Answer 4

Assuming valid close status is either "COMPLETED" or "CANCELLED", you can try following SQL.
SELECT
A1.JobID,
sum(CASE WHEN A1.Status_code = 'CREATED' THEN 1 ELSE 0 END) AS CREATED,
sum(CASE WHEN A1.Status_code = 'CANCELLED' THEN 1 ELSE 0 END) AS CANCELLED,
(
SUM(CASE WHEN A1.Status_code = 'CREATED' THEN 1 ELSE 0 END)
- sum(CASE WHEN A1.Status_code = 'CANCELLED' THEN 1 ELSE 0 END)
- sum(CASE WHEN A1.Status_code = 'COMPLETED' THEN 1 ELSE 0 END)
) AS OPEN
FROM SCHEMA.TABLE A1
GROUP BY A1.JobID