數(shù)據(jù)庫原理第三章作業(yè)-資料下載頁
2025-06-25 07:21本頁面
【正文】 SCADE, Isbn char (20) PRIMARY KEYCONSTRAINT Isbn_constREFERENCES Book( Isbn)ON DELETE CASCADEON UPDATE CASCADE, Pdate datetime NOT NULL)(4)CREATE VIEW BookviewASSELECT Isbn,Bname,Bprice,Pid,Aid,EidFROM Publisher NATURAL JOIN BookWHERE like ‘%成都市%’(5)①關(guān)系代數(shù)表達式：πIsbn,Bname（σPname = XNJDP（Publisher Editor Book）∩σEname = MTQ（Publisher Editor Book））SQL：SELECT Isbn,BnameFROM Publisher NATURAL JOIN Editor NATURAL JOIN BookWHERE Pname = ‘XNJDP’ AND Ename = ‘MTQ’②關(guān)系代數(shù)表達式：πIsbn,Bname（σAgender = 男（Publisher Author Book CB）∩σPname = XNJDP（Publisher Author Book CB）∩σPdate = 20080101（Publisher Author Book CB）∩σPdate = 20081231（Publisher Author Book CB））SQL：SELECT Isbn,BnameFROM Publisher NATURAL JOIN Author NATURAL JOIN Book NATURAL JOIN CBWHERE Agender = ‘男’ AND Pname = ‘XNJDP’ AND Pdate = ‘20080101’ AND Pdate = ‘20081231’③關(guān)系代數(shù)表達式：πIsbn,Bname（σEgender = 女（Publisher Editor Book）∩σBprice = 20（Publisher Editor Book）∩σBprice = 40（Publisher Editor Book））SQL：SELECT Isbn,BnameFROM Publisher NATURAL JOIN Editor NATURAL JOIN BookWHERE Egender = ‘女’ AND Bprice = 20 AND Bprice = 40
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