如何在字符串中去除重复值?

Question

本帖最后由 wh81666825 于 2011-08-15 11:11:14 编辑

Answer 1

distinctgroup by + sum参考

Answer 2

            string str = ",1,1,1,2,2,2,3,3,4,5,6,7,8,9,123,234,1001,1003,1004,1001,";
            string[] result = str.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
            List<string> list = new List<string>();
            foreach (string s in result)
            {
                if (!list.Contains(s))
                    list.Add(s);
            }
            Console.WriteLine(",{0},", string.Join(",", list.ToArray()));

Answer 3

            string str = ",1,1,1,2,2,2,3,3,4,5,6,7,8,9,123,234,1001,1003,1004,1001,";
            Console.WriteLine(",{0},", string.Join(",", str.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries).Distinct().ToArray()));
            Console.ReadLine();

Answer 4

select top 1 列 from 表 group by 列

Answer 5

SQL中处理你直接Select distinct 不就行了么？

Answer 6

SQL中用“SELECT DISTINCT 字段名 FROM 表名”就可以了，但是这是针对逗号分隔的不同值而言，如果LZ的这一整串字符串是一个值的话，SQL就傻了，那么只好取出来放到一个变量中，假设是str，用str.Split(',')分隔成一个字符串数组，string[] arrStr=str.Split(',');然后用2楼得方法进行处理。这是个思路，VB.NET语法没接触过，楼主见谅。

Answer 7

alter function test(@str varchar(200))
returns varchar(200)
as
begin
declare @result varchar(200),@temp varchar(100)
set @result=''
set @temp=''
while(charindex(',',@str)<>0)
begin
set @temp=substring(@str,1,charindex(',',@str))
if(charindex(@temp,@result)<=0)
set @result=@result+@temp
set @str=stuff(@str,1,charindex(',',@str),'')
end
return @result
end
select dbo.test(',1,1,1,2,2,2,3,3,4,5,6,7,8,9,123,234,1001,1003,1004,1001,')
--,1,2,3,4,5,6,7,8,9,123,234,1001,1003,1004,