Make sure your pk of utilizador table is of IDENTITY typeie.user_id number(10) not null IDENTITY(1,1)INSERT INTO utilizador (user_nome,...)VALUES('User1',...)SELECT @UserID=SCOPE_IDENTITY()SELECT f.film_nome,--list all film names rented/bought by user CASE WHEN a.alg_comp_def ='A' THEN 'Rent' WHEN a.alg_comp_def ='C' THEN 'Bought' ENDFROM utilizador uINNER JOIN aluguer_compra aON a.alg_comp_user_id= u.user_idINNER JOIN filme fON f.film_id =a.alg_comp_film_idWHERE u.user_id =@UserID