NET字符串的分割,该如何处理

NET字符串的分割
我现在有一个字符串
如str="厦门,泉州,福州"

要把这个str放在sql里做条件

如
select * from table where shengfen in ('厦门','泉州','福州')

请问一下要怎么实现呢!!请写一下详细一点哦！！！

[解决办法]
select * from table where shengfen in ('厦门,泉州,福州') 
这样就可以了。

[解决办法]
str = "'" + str.Replace(",","','") + "'";

 sql = "select * from table where shengfen in ("
+ str + ")"
[解决办法]

C# code

str="厦门,泉州,福州" string[] arrStr = str.split(',');string sql = "select   *   from   table   where   shengfen   in   (";foreach (string s in arrStr){sql+="'"+s+"',";}sql = sql.remove(sql.length-1);sql+=")";
[解决办法]
QUOTE:str=",厦门,泉州,福州"   是这样子的  
-------------------
那就先将这个字符串去掉第一个逗号
str = str.substring(1);
[解决办法]
str="厦门,泉州,福州"  
string[] arrStr = str.split(',');
string sql = "select   *   from   table   where   shengfen   in   (";
foreach (string s in arrStr)
{
sql+="'"+s+"',";
}
sql = sql.substr(sql.length-1);
sql+=")";