Question

We have a staging table (DB2) that receives production numbers on a daily basis from our plant.

Because of the occasional network outage, there may be days we receive no data. I am trying to create a sql query to retrieve the days but it is not working out

SELECT MODDATE,
COUNT(DISTINCT EWDF) AS COUNT 
FROM PROD_FACT 
WHERE MODDATE=CURRENT_DATE - 7 DAYS 
GROUP BY MODDATE 
HAVING COUNT(DISTINCT EWDF)=0

I was expecting something like this

MODDATE    COUNT          
---------- -----------
09/30/2011     0

  1 record(s) selected.

but to no avail. I get no rows returned. What am I missing??

Answer 1

You probably need to have a sub query and use a not in.

Perhaps something like this:

select prod_fact.moddate
from
prod_fact
where
prod_fact.moddate not in
(
  SELECT distinct MODDATE
  FROM PROD_FACT 
  WHERE MODDATE = CURRENT_DATE - 7 DAYS 
)