请问这种合并怎么写。
字段1字段2字段3
a
b
c
从SQL 查询出来如上，想把它合并到如下：
字段4
a
b
c
请问怎么合并呢？
[解决办法]
----------------------------
-- Author :DBA_Huangzj
-- Date :2013-01-08 16:23:26
-- Version:
-- Microsoft SQL Server 2008 R2 (SP1) - 10.50.2500.0 (X64)
--Jun 17 2011 00:54:03
--Copyright (c) Microsoft Corporation
--Enterprise Edition (64-bit) on Windows NT 6.1 <X64> (Build 7601: Service Pack 1, v.721)
--
----------------------------
--> 测试数据：[huang]
if object_id('[huang]') is not null drop table [huang]
go
create table [huang]([字段1] varchar(1),[字段2] varchar(1),[字段3] varchar(1))
insert [huang]
select 'a',null,null union all
select null,'b',null union all
select null,NULL,'c'
--------------开始查询--------------------------
select COALESCE([字段1],[字段2],[字段3])
from [huang]
----------------结果----------------------------
/*
----
a
b
c
(3 行受影响)
*/
