check if a column contains ALL the values of another column - Mysql

Question

Let\'s suppose I have a table T1 with people IDs and other stuff IDs, as the following

Table: T1
personID | stuffID 
    1    |    1
    1    |    2
    1            


        

Answer 1

select personID
from T1
where stuffID in (select stuffID from t2)
group by personID
having count(distinct stuffID) = (select count(*) from t2)

I.e pick a person's stuffids which are in T2, count them (distinct only), and verify same number as in t2.