select A.aa,B.bb,D.dd
from A innerjoin( B inner join( c inner join d on C.c1=D.c1) on c.a1=B.a1) on B.a1 =A.a1
这样写对不对?????
from A innerjoin( B inner join( c inner join d on C.c1=D.c1) on c.a1=B.a1) on B.a1 =A.a1
这样写对不对?????
http://www.csdn.net/expert/topic/345/345130.shtm