EMP : NO,AREA(AREA是个标志位,0 本国人, 1 外国人)
11, 0
12, 1
LOCAL : NO ,NAME
11, ZHANGSAN
12, LISI
13, WANGWU
FOREIGN : NO,NAME
11, JAKE
12, TOM
13, ROB
-------------------------------------------------------------------------
Select
a.No,
decode(a.area,0,b.Name,c.Name) Name
From emp a,Local b,Foreign c
Where a.No=b.No(+)
And a.No=c.No(+)
-----------------------------------------------------
Select
a.No,
decode(a.area,0,b.Name,1,c.Name) Name
From emp a,Local b,Foreign c
Where a.No=b.No(+)
And a.No=c.No(+)
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