Est-ce la bonne façon de créer une assertion SQL?

Question

Afin de faire le type d'affirmation suivant

create assertion assert  
check "EMPTY SET" = (select User         
     from Video  
     where date=current_date()  
     group by user  
having count(*) >= 10

Cette affirmation est-elle correcte?

create assertion assert  
check  0 = (select count(*)  
     from Video  
     where date=current_date()  
     group by user  
having count(*) >= 10