It's called a JOIN. You really should read up on SQL enough to understand at least simple JOINs.
Code:
SELECT floorid, floors.name, buildings.name
FROM floors, buildings
WHERE floors.buildingID = buildings.buildingID
ORDER BY floorid
That can also be written as:
Code:
SELECT floorid, floors.name, buildings.name
FROM floors INNER JOIN buildings
ON floors.buildingID = buildings.buildingID
ORDER BY floorid
Please tell me this is not homework.