Hello All!
I am wondering if there is a clever way to know which WHERE or JOIN CONDITION results in no data returned.
Suppose, there is a query:
SELECT *
FROM tab1 t1
JOIN tab2 t2 ON t2.id=t1.id
JOIN tab3 t3 ON t3.id=t2.id
JOIN tab4 t4 ON t4.id=t3.id;
If the query returned no rows how may one know which ON condition was the reason?
Best regards,
Jacek