select A.T_num,B.R_Length,B.R_Width from Table3 A Left Jion Table1 B On A.T_Num=B.R_num
Union
select A.T_num,B.F_Length,B.F_Width from Table3 A Left Jion Table1 B On A.T_Num=B.F_num
两站表合并??
select * FROM TABLE1 where riqi> and riqi<
UNION ALL
select * FROM TABLE1 where riqi> and riqi<
建视图~~
如果你不想用视图:
select * from (select * from score1999 union all select * from score2000) tem where 你的条件
效率可能会底一点!