sqlserver分割字符串为行数据

create function f_str_split(@str_in AS VARCHAR(max),@split as varchar(2) =',')
 RETURNS @keylst TABLE(keyval varchar (50))
BEGIN
 declare @idx1 int,@idx2 int,@key varchar(50)
 set @idx1 = 1
 set @idx2 = 0
 if isnull(@split,'') = '' set @split = '|'
 if right(@str_in,1) <> @split set @str_in = @str_in + @split 
 while 1=1
    begin
  set @idx2 = CharIndex(@split,@str_in,@idx2 + 1);
  if @idx2 <= 0 break
  --print '@idx1 ' + cast(@idx1 as varchar) + '   @idx2 ' + cast(@idx2 as varchar)
  insert into @keylst select substring(@str_in,@idx1,@idx2 - @idx1);
  --print @key;  
  set @idx1 = @idx2 + 1;
 end
 return;
end
go
select * from f_str_split('1,2,3,4',',')