問題：

     如何編寫SQL完成如下需求：一張表T（A,B,C)按照B欄位降冪排序，然後求提取其中的部分值m--n

測試：

CREATE TABLE T(A INT,B INT,C INT);

INSERT INTO T VALUES(1,6,9);

INSERT INTO T VALUES(2,7,8);

INSERT INTO T VALUES(3,5,7);

INSERT INTO T VALUES(4,4,6);

INSERT INTO T VALUES(5,8,5);

INSERT INTO T VALUES(6,6,0);

INSERT INTO T VALUES(7,7,4);

INSERT INTO T VALUES(8,3,5);

INSERT INTO T VALUES(9,2,3);

INSERT INTO T VALUES(0,9,2);

COMMIT;

SQL: /* Formatted on 2013/02/27 09:04 (Formatter Plus v4.8.8) */

   SELECT A,B,C FROM

       ( SELECT ROWNUM RUNM,M.* FROM

         (SELECT * FROM T ORDER BY B DESC) M

        ) WHERE RUNM>=M AND RUNM<=N

/