Neither; join table b to table a twice. See if this gives you an idea, from something I'm working on where I needed to denormalize data in a locations table (note this is from SQL Server, Access syntax may differ slightly):
Code:
SELECT PU.FieldName As PickupLocation, DO.FieldName as DropoffLocation
FROM ResSegments Seg
--SC splits the pickup and dropoff addresses into a related table, these allow denormalization
--type 0 is pickup, type 1 is dropoff, type 2 is for stops, not used here
LEFT JOIN ResSegmentLocations PU
ON Seg.SegmentRowId = PU.SegmentRowId And PU.LocationPhaseType = 0
LEFT JOIN ResSegmentLocations DO
ON Seg.SegmentRowId = DO.SegmentRowId And DO.LocationPhaseType = 1