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add constraint PK_CLA_NUM check (Number>1 and Number<100) 3) ÉèÖÃMonitorΪÍâÂë

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add constraint PK_CLA_MON

foreign key (Monitor) references Student (Sno) 4. Ϊ³É¼¨Grade ±í½¨Á¢ÍêÕûÐÔÔ¼Êø 1) ÉèÖÃSnoºÍCnoΪÖ÷ÊôÐÔ¡¢Íâ¼ü¡£

½¨Á¢FOREIGN KEYÔ¼Êø£¬ÉèÖÃSnoºÍCnoΪÍâÂësqlÓï¾äΪ¡£ alter table Grade

add constraint PK_GRA_SNO

foreign key (Sno) references Student (Sno) alter table Grade

add constraint PK_GRA_CNO

foreign key (Cno) references Cource(Cno) ÉèÖÃSno,CnoΪÖ÷Âë

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alter table Grade add constraint PK_GRA_PRI primary key (Sno,Cno) 2) ÉèÖÃGmarkΪ´óÓÚ1СÓÚ100¡£ ½¨Á¢CHECKÔ¼Êø.sqlÓï¾äΪ

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alter table Grade

add constraint PK_GRA_GMA check (Gmark>1 and Gmark<100)

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