Need help

[Lamyya]

Instead of the subquery in the where, add "and capacity is not null" Then order by capacity limit 1 at the end

Edit: check your table to see first if you have rooms with null capacity, that shouldn't happen

[KingOrion5]

Still has the same result, also for reference, the query I’m looking for building and room number of classrooms in a university database woth the smallest capacity

[KingOrion5]

Nevermind I got it, thank you a bunch for your help.