There are four through express trains a day, and all have dining cars (short on amenities? European trains haven't had parlor cars since 1970 or so). Three of them go to the station on the edge of downtown, since they continue on/connect to trains to Germany, and one train terminates at the main Prague station. These trains have either open or compartment seating (or both), but it's inaccurate to say that they "still" have compartments, since the newest Austrian cars have only compartment seating.