rocky_498 (9/28/2016)
I am using AND not OR. Correct me If I am wrong.WHERE CID IS NOT NULL
AND MID IS NOT NULL
This means when both conditions met
if my query is
WHERE (CID IS NOT NULL
OR
MID IS NOT NULL)
In OR case if either one is Null
am I missing something ?
When using AND, both conditions need to be met... The 2nd row fails the 2nd condition... which is why it was filtered out.
If you use the OR only one of the conditions needs to be met... So, in this case CID is not null, preventing the row from being filtered out by the "MID IS NOT NULL".