两个视图的连接
两个表a(a1,a2,a3) ,b(b1,b2,b3) 想把他们连接起来,a1与b1,a2与b2 字段相同,数据有可能并不相等,a (2007-04-15,11,12),(2007-04-16,11,12),(2007-04-13,11,12) b (2007-14-15,11,16) ,(2007-14-16,11,16),(2007-14-18,11,16)
合起来c数据就是
c1 c2 c3 c4
2007-04-13 11 12 0
2007-04-15 11 12 16
2007-04-16 11 12 16
2007-04-18 11 0 16
------解决方案--------------------create visew ab (select a.a1 a.a2 a.a3 b.b1 b.b2 from a ,b )
------解决方案--------------------学习了