All DSLRs focus using the lens. None have an in-body focusing system where the sensor or lens flange move. Such a system will not work in an SLR configuration. If the sensor moved, the focusing screen and other related elements would also have to move. If the lens flange moved it would have to be able to haul any of the available lenses back an forth, both requiring a lot of horse power and would work too slowly to be practical.
The only body vs. lens differences in DSLRs, or AF film SLRs, is the placement of the motor. Some systems rely on each lens having its own motor (e.g. Canon DSLRs and EOS film bodies), some rely only the body having the motor, and some systems support both arrangements (e.g. Nikon, where most recent bodies support either type of lens but some older bodies bodies only support lenses that use the body motor and some like the D40/40x/60 support only lenses with motors).