嵌套游标的使用

declare cur1 cursor for
    select ... from table_name1 where ...group by / order by ...
     open cur1
    FETCH   NEXT   FROM   cur1  INTO  ...
     while (@@FETCH_STATUS = 0 )
       begin
        ....
           declare cur2 cursor for
              select ... from table_name2 where ...group by / order by ...
               set @sql='select ... from table_name2 where ...group by / order by ...'
               exec @sql
                open cur2
                  FETCH   NEXT   FROM   cur2  INTO  ...
                   while (@@FETCH_STATUS = 0 )
                      begin
                         ....
                        FETCH   NEXT   FROM   cur2  INTO  ...
                      end
                         ....
               close cur2
             DEALLOCATE cur2

        FETCH   NEXT   FROM   cur1  INTO  ...
      end
     close cur1
   deallocate cur1