講解數(shù)據(jù)庫(kù)原理與應(yīng)用教程（第三版）第四章課后習(xí)題答案

1.SELECT*FROMStudent結(jié)果：2.SELECTSname姓名,Sage年齡FROMStudentWHERESdept='計(jì)算機(jī)系'結(jié)果：3.SELECTSno學(xué)號(hào),Cno課程號(hào),Grade成績(jī)FROMSCWHEREGradeBETWEEN70AND804.SELECTSname姓名,Sage年齡FROMStudentWHERESdept='計(jì)算機(jī)系'ANDSage>=18ANDSage<=20ANDSsex='男'5.SELECTMAX(Grade)最高分?jǐn)?shù)FROMSCWHERECno='c01'6.SELECTMAX(Sage)最大年齡,MIN(Sage)最小年齡FROMStudentWHERESdept='計(jì)算機(jī)系'7.SELECTSdept系名,COUNT(*)學(xué)生人數(shù)FROMStudentGROUPBYSdept8.SELECTCname課程名,COUNT(*)選課門(mén)數(shù),MAX(Grade)最高分FROMCourse,SCGROUPBYCname9.SELECTSno學(xué)號(hào),COUNT(*)選課門(mén)數(shù),SUM(Grade)總成績(jī)FROMSCGROUPBYSnoORDERBY'選課門(mén)數(shù)'ASC10.SELECTSno學(xué)號(hào),SUM(Grade)總成績(jī)FROMSCGROUPBYSnoHAVINGSUM(Grade)>20010.CREATTABLEBOOK（Snobooknchar(6)PRIMARYKEY,Snamebooknvarchar(30)NBOTNULL,Writerchar(10)NOTNULL,Timesmalldatetime,Pricenumeric(3,1))CREATTABLEBOOKSHOP(Snoshopnchar(6)PRIMARYKEY,Snameshopnvarchar(30)NOTNULL,Telchar（8）CHECK(Tel=0ANDTel<=9),Placenchar(40),Snoemailchar(6))CREATTABLEBOOKSELL（Snobooknchar(6)NOTNULL,Snoshopnchar(6)NOTNULL,SelltimesmalltimeNOTNULL,Snoselltinyint,PRIMARYKEY(Snobook,Snoshop,Selltime),FOREIGNKEY(Snobook)REFERENCESBOOK(Snobook),FOREIGNKEY(Snoshop)REFERENCESBOOK(BOOKSHOP))11.ALTERTABLEBOOKADDNomberintADDCONSTRAINTDF-NomberCHECK(Nomber>1000)12.ALTERTABLEBOOKSHOPDROP