日期:2014-05-17 浏览次数:21118 次
with t as(
select 1 A,2 B from dual
union all
select null,3 from dual
union all
select 4,null from dual
)select nvl(A,B) from t
NVL(A,B)
----------
1
3
4
------解决方案--------------------
2中简单方法
nvl(A,B)
decode(A,null,B,A)