0 votes 0 votes a) 0 b) 1 c) 2 d) 3 Databases sql query databases + – Nirmal Gaur asked Sep 15, 2018 Nirmal Gaur 548 views answer comment Share Follow See all 7 Comments See all 7 7 Comments reply Shaik Masthan commented Sep 15, 2018 reply Follow Share option d :- 3 1 votes 1 votes Nirmal Gaur commented Sep 15, 2018 reply Follow Share @shaik Masthan, Does NOT IN connective on empty set returns TRUE? please elaborate 0 votes 0 votes Shaik Masthan commented Sep 15, 2018 reply Follow Share as per my knowledge yes. take each row, and evaluate. what happens NOT IN is replaced by IN operator? first tuple from A, (12,A,60) taken, condition age IN ( some values ) if age = value1 or age = value2 or age = value3 or ........ then return true. what happens in case of NOT IN if age ≠ value1 and age ≠ value2 and age ≠ value3 and ........ then return true. yes my value is not matched by any value (in case of empty table also) ===> return true. for confirmation i run it on W3 Schools.com also. NOT IN (EMPTY TABLE) ====> always true. IN (EMPTY TABLE) ====> always false. 1 votes 1 votes Nirmal Gaur commented Sep 15, 2018 reply Follow Share yes my value is not matched by any value (in case of empty table also) ===> return true. That explains it beautifully...Thanks a lot brother :) 0 votes 0 votes BASANT KUMAR commented Sep 16, 2018 reply Follow Share can you tell me what happen when i replace NOTIN by EXCEPT is it 3??? 0 votes 0 votes Shaik Masthan commented Sep 16, 2018 reply Follow Share EXCEPT is a SET operator, you can't apply it here. i hope you want to know (Set1) except (Set2) 1) if Set2 is empty, then result is Set1 2) if Set1 is empty, then result is empty 0 votes 0 votes BASANT KUMAR commented Sep 16, 2018 reply Follow Share got it.i forget the basic concept.thnx 0 votes 0 votes Please log in or register to add a comment.