SQL 语句请教

[星际]

我有一张表记录的是用户选择的产品，数据类型为varchar(200)，数据类似：1,2,3,4,20,21,22

这个数据对应的产品表的自增ID集合
ID Name
1 产品A
2 产品B
3 产品C

请问我如何快速遍历出某个产品被选择的次数，用like可能会出现 选择产品ID为1的，其它产品ID：11,21,31，这种会一起出来。

求大虾指教，谢谢。

[htl258_Tony]

select a.name,count(1) as  遍历次数
from ta a
  join tb b 
    on charindex(','+ltrim(a.id)+',',','+b.col+',')>0
group by a.name

[lovezx1028]

[Quote=引用 1 楼 htl258 的回复:]

SQL code
select a.name,count(1) as 遍历次数
from ta a
join tb b
on charindex(','+ltrim(a.id)+',',','+b.col+',')>0
group by a.name
[/Quote] 顶一个/

[htl258_Tony]

----------------------------------------------------------------------------------
-- Author : htl258(Tony)
-- Date   : 2010-05-04 10:20:37
-- Version: Microsoft SQL Server 2008 (RTM) - 10.0.1600.22 (Intel X86) 
--          Jul  9 2008 14:43:34 
--          Copyright (c) 1988-2008 Microsoft Corporation
--          Developer Edition on Windows NT 5.1 <X86> (Build 2600: Service Pack 3)
-- Blog   : http://blog.csdn.net/htl258
----------------------------------------------------------------------------------

--> 生成测试数据表: [ta]
IF OBJECT_ID('[ta]') IS NOT NULL
	DROP TABLE [ta]
GO
CREATE TABLE [ta] ([ID] [int],[Name] [nvarchar](10))
INSERT INTO [ta]
SELECT '1','产品A' UNION ALL
SELECT '2','产品B' UNION ALL
SELECT '3','产品C'

--> 生成测试数据表: [tb]
IF OBJECT_ID('[tb]') IS NOT NULL
	DROP TABLE [tb]
GO
CREATE TABLE [tb] ([id] [int],[col] [nvarchar](20))
INSERT INTO [tb]
SELECT '1','1,2,3,4,20,21,22' UNION ALL
SELECT '2','2,3,4,5,6' UNION ALL
SELECT '3','5,6,7'

--SELECT * FROM [ta]
--SELECT * FROM [tb]

-->SQL查询如下:
select a.name 产品名称,count(1) as  遍历次数
from ta a
  join tb b 
    on charindex(','+ltrim(a.id)+',',','+b.col+',')>0
group by a.name
/*
产品名称       遍历次数
---------- -----------
产品A        1
产品B        2
产品C        2

(3 行受影响)
*/

[--小F--]

select
  a.name,count(1) as 次数
from
  a,b
where 
  charindex(','+ltrim(a.id)+',',','+b.col+',')>0
group by
  a.name