create function fn_find(@find varchar(8000), @str varchar(8000), @n smallint)      returns int  as  begin      if @n < 1 return (0)      declare @start smallint, @count smallint, @index smallint, @len smallint      set @index = charindex(@find, @str)      if @index = 0 return (0)      else select @count = 1, @len = len(@find)      while @index > 0 and @count < @n          begin              set @start = @index + @len              select @index = charindex(@find, @str, @start), @count = @count + 1          end      if @count < @n set @index = 0      return (@index)  end  go      declare @str varchar(100)  set @str=‘A,B,C,D,A,B,C,D,C,D,B,A,C,E‘    select dbo.fn_find(‘A‘,@str,1) as one, dbo.fn_find(‘A‘,@str,2) as two, dbo.fn_find(‘A‘,@str,3) as three, dbo.fn_find(‘A‘,@str,4) as four  /*  one         two         three       four          ----------- ----------- ----------- -----------   1           9           23          0  */