| Subject | Is there any logical difference? | 
|---|---|
| Author | liviuslivius | 
| Post date | 2019-08-09T15:35:55Z | 
Hi
I have the query where this make a difference and i do not know why...
Is there any logical difference between this two statements?
1. -------------------------
NOT 
     (
     EXISTS()
     OR
     EXISTS()
     )
2. -------------------------
CASE WHEN EXISTS() THEN 1 ELSE 0 
+
CASE WHEN EXISTS() THEN 1 ELSE 0
= 0
----------------------------------------
the query plans are exactly the same. 
First query return nothing, second one return 211 records.
regards
Karol Beieniaszewski