50分 解决一个SQL查询问题 - MS-SQL Server / 基础类

SQL code:

有一个表A 里面有三个字段
a int
b int
c int

表里的数据为

a b c
________
3 9 5
5 2 7
6 3 8



用最简单的方法查出表里最大的数据

只要查询结果为 9 即刻给分.................

---

SQL code:
select
max(a)
from
(select a from tb
union all
select b as a from tb
union all
select c as a from tb
)t

---

SQL code:
----------------------------------------------------------------
-- Author :fredrickhu(小F，向高手学习)
-- Date :2010-05-06 16:45:10
-- Version:
-- Microsoft SQL Server 2005 - 9.00.4035.00 (Intel X86)
-- Nov 24 2008 13:01:59
-- Copyright (c) 1988-2005 Microsoft Corporation
-- Developer Edition on Windows NT 5.1 (Build 2600: Service Pack 3)
--
----------------------------------------------------------------
--> 测试数据：[tb]
if object_id('[tb]') is not null drop table [tb]
go
create table [tb]([a] int,[b] int,[c] int)
insert [tb]
select 3,9,5 union all
select 5,2,7 union all
select 6,3,8
--------------开始查询--------------------------
select
max(a)
from
(select a from tb
union all
select b a