access如何查询多个字段的最大值

[lp923]

access数据表，其中有多个双精度类型的字段，如何查询出这多个字段的最大值，只要得到最大值
a b c
1 3 5
2 8 10
33 20 18
我要得到a，b，c三个字段的最大值33
如何写sql语句

[hongqi162]

select max(t.d) from 
(
select a as d from tablename union
select b as d from tablename union
select c as d from tablename
)t

[lp923]

[Quote=引用 1 楼 hongqi162 的回复:]
SQL codeselect max(t.d) from
(
select a as d from tablename union
select b as d from tablename union
select c as d from tablename
)t
[/Quote]

知道了，谢谢你