Base query problem

I am trying to create my first query on base.

It has two criterion ie. I want to end up with a list of people with a particular membership type (Friend Member) whose mail preference is ‘Post’. It works fine when I just use the mail preference field. But when I add ‘Friend Member’ to the Member Type field and run the query it is blank. All the other fields seem to work OK - it’s just the member type one which doesn’t. It should be simple, but I can’t work out what I’m doing wrong. Any help gratefully received.

Look at the result of the working “friend member” query. Do you see any entries which prefer post? This is the usual reason why a query would return empty set (or “blank”).

Check for leading/trailing spaces in the data you filter on. Invisible to you, but may be significant to the query.

Thankyou! You were right. The problem was caused by trailing spaces in entries in the problem field. I have deleted them and now it works.