A表数据(id,name)
(1,上海)
(2,北京)
B表数据(id,Aid,name)
(1,1,杨浦区)
(2,1,黄埔区)
(3,2,崇文区)建立视图后(id,name,nodekey,parentkey)
(1,杨浦区,1,1)
(2,黄埔区,2,1)
(3,崇文区,3,2)
(4,上海,1,-1)
(5,北京,2,-1)
作为一个自连接的视图
(1,上海)
(2,北京)
B表数据(id,Aid,name)
(1,1,杨浦区)
(2,1,黄埔区)
(3,2,崇文区)建立视图后(id,name,nodekey,parentkey)
(1,杨浦区,1,1)
(2,黄埔区,2,1)
(3,崇文区,3,2)
(4,上海,1,-1)
(5,北京,2,-1)
作为一个自连接的视图
SELECT rownum id, NAME, id nodekey, parentkey
FROM (SELECT id, NAME, aid parentkey
FROM b
UNION ALL
SELECT id, NAME, -1 parentkey FROM a);
create view the_else as
select rownum id,name,id nodekey, aid parentkey
from (select name, id, aid
from b
union all
select name, id, -1 aid from a)
哈哈
select rownum id,name,id nodekey, aid parentkey
from (select name, id, aid
from b
union
select name, id, -1 aid from a)
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