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
/
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