Just correcting myself here :

In my previous post I assume that you are creating a bitmap so I suggested you do something like this :

Declare @BitMap as int

set @BitMap = 0

Select @BitMap = @BitMap | MyBit from

(

Select 1 as MyBit

union all

Select 2 as MyBit

union all

Select 4 as MyBit

) A

Select @BitMap as BitMap

/*but if all the attributes are unique you could also do it like this which may be a little less safe (have little experience with bitmaps)*/

Select sum(MyBit) as BitMap from

(

Select 1 as MyBit

union all

Select 2 as MyBit

union all

Select 4 as MyBit

) A