How to run concurring SQL query?

Question

I am trying to run this sql query.

SELECT * FROM AverageFeedInfo WHERE No = (
SELECT No FROM UserResponse2 where Not Complain = '' )

When I run SELECT No FROM UserResponse2 where Not Complain = '' individually I have result 2 and 6, but if I run this

SELECT * FROM AverageFeedInfo WHERE No = (
SELECT No FROM UserResponse2 where Not Complain = '' )

I have only the result for 2 not for 6. Is it possible to get the answer for both 2 and 6. To be more clear is it possible to run the sql query like

SELECT * FROM AverageFeedInfo WHERE No = 2 or No = 6

Answer 1

Generally, when checking set membership in a SQL-based context use of an IN operator is more appropriate than =.