Hi Caroline,

Simple:
if this rules are true:
- BETWEEN(itemId,0,31) is true
- CustID,itemId is unique

this:

Select CustID from Subs ;
where itemId=1;   
and CustId in (select CustId from Subs where itemId=2) ;
and CustID Not IN (select distinct CustId from Subs where itemid NOT IN (1,2))

and

Select CustID from Subs GROUP BY CustID HAVING SUM(BITSET(0,itemId))=6

are equal.

Fabio