I already have parenthiesis on the query, but that query itself is wrong it gives multiple records for not null columns.

Thanks Paul for your response

I have requirements where there is an amount which depends on several foreign keys from several primary keys.

for e.g. I have locations master table, machine types...

Thanks Simon, Thats brilliant answer, but now another complications.

what if I have 6 columns as a combination.

for e.g. T1 has 6 columns more and T3 has 6 nullable columns...

Thanks for your reply, but your GROUP BY query also gives me 4 records, what I want to achieve is get the Y if T3 has col2 as NULL but...

Thanks Mark for your help 🙂 I should denormalise then.

Thanks Mark, yes you are exactly correct, I am looking the Machine data,

From your answer , do you mean to say I should put all the Primary keys in Collections...