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分享如何得到三张表的全连接?
我有三张表,
A表:
A1
---
a
c
d
B表:
B1
---
b
e
f
C表:
C1
---
a
c
e
如何能得到三张表的全连接?
A1 B1 C1
--------
A表:
A1
---
a
c
d
B表:
B1
---
b
e
f
C表:
C1
---
a
c
e
如何能得到三张表的全连接?
A1 B1 C1
--------
...全文
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yanling1984 2007-10-29
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full outer join
sutdy 2007-10-29
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select * from a1,b1,c1
foger 2007-10-09
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select *
from C1 e full outer join A1 d
on (e.a=d.a and e.c=d.c)
full outer join B1 f
on (e.e=f.e)
from C1 e full outer join A1 d
on (e.a=d.a and e.c=d.c)
full outer join B1 f
on (e.e=f.e)
ruihuahan 2007-10-09
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如果要的是三表的笛卡尔积，应该使用cross join
