sqlserver 分离字符串问题

 @H_404_5@

ALTER FUNCTION [dbo].[FDealName] ( @cvAllList varchar(50))
  RETURNS varchar(50) 
  AS  
    BEGIN 
        declare @biLoc int
        declare @cvList varchar(max)
        declare @retName varchar(max)
        declare @retAllname varchar(max)
        set @retAllname=''
        SELECT @biLoc = CHARINDEX(',',@cvAllList)
     WHILE (@biLoc > 0)
     BEGIN
      -- 取分号前部分
      SELECT @cvList = LEFT(@cvAllList,@biLoc - 1)
      -- do something
      -- 取分号后部分
      SELECT @cvAllList = RIGHT(@cvAllList,LEN(@cvAllList)-@biLoc) 
      if  @cvList !=''
      begin 
      select @retName =','+ techName from Technican_Info where TechnicanID =@cvList
      select @retAllname = @retAllname + @retName 
      end          
      -- 搜索下一个分号
      SELECT @biLoc = CHARINDEX(',@cvAllList)
     END
        RETURN @retAllname
    END