/*标题：分解字符串并查询相关数据作者：爱新觉罗.毓华(十八年风雨,守得冰山雪莲花开) 时间：2008-03-18地点：广东深圳说明：通过使用函数等方法分解字符串查询相关数据。
问题：通过分解一个带某种符号分隔的字符串在数据库中查找相关数据。例如 @str = '1,2,3',查询下表得到记录1,4,5,6ID TypeID1 1,2,3,4,5,6,7,8,9,10,11,122 2,3 3 3,7,8,9 4 2,6 5 4,56 6,7 */-----------------------------create table tb (ID int , TypeID varchar(30)) insert into tb values(1 , '1,2,3,4,5,6,7,8,9,10,11,12') insert into tb values(2 , '2,3') insert into tb values(3 , '3,7,8,9') insert into tb values(4 , '2,6') insert into tb values(5 , '4,5')insert into tb values(6 , '6,7')go-------------------------------如果仅仅是一个,如@str = '1'.declare @str as varchar(30)set @str = '1'select * from tb where charindex(',' + @str + ',' , ',' + TypeID + ',') > 0select * from tb where ',' + TypeID + ',' like '%,' + @str + ',%'/*ID TypeID ----------- ------------------------------ 1 1,2,3,4,5,6,7,8,9,10,11,12（所影响的行数为 1 行）*/
-------------------------------如果包含两个,如@str = '1,2'.declare @str as varchar(30)set @str = '1,2'select * from tb where charindex(',' + left(@str , charindex(',' , @str) - 1) + ',' , ',' + typeid + ',') > 0 or charindex(',' + substring(@str , charindex(',' , @str) + 1 , len(@str)) + ',' , ',' + typeid + ',') > 0select * from tb where ',' + typeid + ',' like '%,' + left(@str , charindex(',' , @str) - 1) + ',%' or ',' + typeid + ',' like '%,' + substring(@str , charindex(',' , @str) + 1 , len(@str)) + ',%'/*ID TypeID ----------- ------------------------------ 1 1,2,3,4,5,6,7,8,9,10,11,122 2,34 2,6（所影响的行数为 3 行）*/
---------------------------------------------如果包含三个或四个，用PARSENAME函数来处理.declare @str as varchar(30)set @str = '1,2,3,4'select * from tb where charindex(',' + parsename(replace(@str , ',' , '.') , 4) + ',' , ',' + typeid + ',') > 0 or charindex(',' + parsename(replace(@str , ',' , '.') , 3) + ',' , ',' + typeid + ',') > 0 or charindex(',' + parsename(replace(@str , ',' , '.') , 2) + ',' , ',' + typeid + ',') > 0 or charindex(',' + parsename(replace(@str , ',' , '.') , 1) + ',' , ',' + typeid + ',') > 0 select * from tb where ',' + typeid + ',' like '%,' + parsename(replace(@str , ',' , '.') , 4) + ',%' or ',' + typeid + ',' like '%,' + parsename(replace(@str , ',' , '.') , 3) + ',%' or ',' + typeid + ',' like '%,' + parsename(replace(@str , ',' , '.') , 2) + ',%' or ',' + typeid + ',' like '%,' + parsename(replace(@str , ',' , '.') , 1) + ',%'/*ID TypeID ----------- ------------------------------ 1 1,2,3,4,5,6,7,8,9,10,11,122 2,33 3,7,8,94 2,65 4,5（所影响的行数为 5 行）*/
-----------------------------------------如果超过四个，则只能使用函数或动态SQL来分解并查询数据。/*名称：fn_split函数.功能：实现字符串分隔功能的函数*/create function dbo.fn_split(@inputstr varchar(8000), @seprator varchar(10))returns @temp table (a varchar(200))as begin declare @i int set @inputstr = rtrim(ltrim(@inputstr)) set @i = charindex(@seprator , @inputstr) while @i >= 1 begin insert @temp values(left(@inputstr , @i - 1)) set @inputstr = substring(@inputstr , @i + 1 , len(@inputstr) - @i) set @i = charindex(@seprator , @inputstr) end if @inputstr <> '/' insert @temp values(@inputstr) return endgo
--调用declare @str as varchar(30)set @str = '1,2,3,4,5'
select distinct m.* from tb m,(select * from dbo.fn_split(@str,',')) nwhere charindex(',' + n.a + ',' , ',' + m.typeid + ',') > 0
drop table tbdrop function dbo.fn_split
/*ID TypeID ----------- ------------------------------ 1 1,2,3,4,5,6,7,8,9,10,11,122 2,33 3,7,8,94 2,65 4,5（所影响的行数为 5 行）*/
--------------------------------------------使用动态SQL的语句。declare @str varchar(200)declare @sql as varchar(1000)set @str = '1,2,3,4,5'set @sql = 'select ''' + replace(@str , ',' , ''' as id union all select ''')set @sql = @sql + ''''set @sql = 'select distinct a.* from tb a , (' + @sql + ') b where charindex(' + ''','' + b.id + ' + ''',''' + ' , ' + ''','' + a.typeid + ' + ''',''' + ') > 0 'exec (@sql)/*ID TypeID ----------- ------------------------------ 1 1,2,3,4,5,6,7,8,9,10,11,122 2,33 3,7,8,94 2,65 4,5（所影响的行数为 5 行）*/
