Z zyg_zm Unregistered / Unconfirmed GUEST, unregistred user! 2002-05-23 #2 用union可以实现交集，差集的话，在加上一些WHERE子句，不过具体怎么实现你还是自己去想想吧， 这问题一下子说不清楚，要通过实践。
天 天真 Unregistered / Unconfirmed GUEST, unregistred user! 2002-05-23 #3 是不是既属于A又属于B的集合？？ 如果是这样的话， select * from (select * from a union select * from b) c, where c.id in (select id from a) and c.id (select id from b)
是不是既属于A又属于B的集合？？ 如果是这样的话， select * from (select * from a union select * from b) c, where c.id in (select id from a) and c.id (select id from b)
S stamm Unregistered / Unconfirmed GUEST, unregistred user! 2002-05-23 #4 to zyg_zm union不是并集的操作吗 我实在是想不出，假设表只有两个字段（name，id）能不能举个例子
Z zyg_zm Unregistered / Unconfirmed GUEST, unregistred user! 2002-05-23 #6 哦，对，union是并集，我刚才看错了，理解错了。这样其实很不好做啊，多用几个 条件语句不行吗，你试试建一个临时表会不会方便一点。 我没办法帮你了，我没时间去试
D drawpharos Unregistered / Unconfirmed GUEST, unregistred user! 2002-05-23 #7 建一个视图，通过设置视图的条件可以实现 Access和MS SQL都支持视图
B book523 Unregistered / Unconfirmed GUEST, unregistred user! 2002-05-23 #8 交集 select * from (select * from a union select * from b) c, where c.id in (select id from a) and c.id (select id from b) 差集 select * from a where a.id not in (select id from b) union select * from b where b.id not in (select id from a)
交集 select * from (select * from a union select * from b) c, where c.id in (select id from a) and c.id (select id from b) 差集 select * from a where a.id not in (select id from b) union select * from b where b.id not in (select id from a)
X xianjun Unregistered / Unconfirmed GUEST, unregistred user! 2002-05-23 #9 Oracle: 交： intersect 并： union、union all 差： minus 如： select * from 表1 intersect select * from 表2
S stamm Unregistered / Unconfirmed GUEST, unregistred user! 2002-05-24 #10 这样情况如何解决 表一 name id aa 123 bb 456 cc 456 表二 name id dd 789 cc 456 ee 456 交集所得的结果应是 name id cc 456 差集所得的结果应是 name id aa 123 bb 456
这样情况如何解决 表一 name id aa 123 bb 456 cc 456 表二 name id dd 789 cc 456 ee 456 交集所得的结果应是 name id cc 456 差集所得的结果应是 name id aa 123 bb 456
T tfnmao Unregistered / Unconfirmed GUEST, unregistred user! 2002-05-29 #11 交集 select a.name a.id from 表1 a,表2 b where a.name=b.name and a.id=b.id 差集用book523的方法
