join 4 table with specified column :     SELECT A.UNITCODE, B.FORMATIONCODE, C.UPPERFORMATIONCODE, D.UPPERFORMATIONCODE FROM UNIT AS A.UNITCODE INNER JOIN FORMATION AS B.FORMATIONCODE INNER JOIN UPPERFORMATION_UNIT AS C.UPPERFORMATION INNER JOIN UPPERFORMATION AS D.UPPERFORMATIONCODE WHERE UNITCODE='7000007'

can you guys help me how to join 4 tables with specified column.. please