数据库实验报告计C104李云霄108490实验1.5(1)grantselectonstudentstopublic(2)grantselect,updateoncoursestopublic(3)grantselect,update(salary)onteacherstouser1withgrantoption(4)grantselect,update(score)onchoicetouser2(5)createviewtvasselecttid,tname,email,salaryfromTEACHERSgrantselectontvtouser2(6)grantselectonteacherstouser2withgrantoption(7)grantselectonteacherstouser3withgrantoptiongrantselectonteacherstouser2withgrantoption正常执行(8)revokeselectonteachersfromuser1cascade操作成功，可以实现删除的级联操作，权限全部取消(9)revokeselect,updateoncoursesfromuser1,user2实验2.1(1)建一张表USESCHOOLCREATETableClass(Class_idvarchar(4),namevarchar(10),deparmentvarchar(20)constraintPK_ClassPrimarykey(Class_id))(2)创建事务T3，嵌套创建T4USEschoolBeginTransactionT3insertintoclassvalues('00001','01CSC','CS')BeginTransactionT4insertintoclassvalues('00001','01CSC','CS')CommitTransactionT4commitTransactionT3T4插入违法，T4终止，整个事务回滚，T3中的插入也被终止实验2.2结果：ondeleterestrict不允许级联操作，数据库不允许删除students表及course表中的对应元组结果：ondeleteSetNULL是将要删除的对应元组的外键置空，而cno和sno是SC表的主键，主键不能为空，所以数据库不允许删除操作(3)创建学生互助表createtablehelp(sidchar(8),snamevarchar(20),help_idchar(8)notnullconstraintPK_helpprimarykey(sid))altertablehelpaddconstraintFK_helpforeignkey(help_id)referenceshelp(help_id)(4)每个部门一个部长，每个部长领导多个部员，每个部有一个部员有评测部长的权利createtableleader(sidchar(9),snamevarchar(20),myleaderchar(9),constraintPK_leaderprimarykey(sid))createtablemonitor(sidchar(9),snamevarchar(20),mymonitorchar(9)constraintPK_monitorprimarykey(sid)constraintFK_monitorforeignkey(mymonitor)referencesleader(sid))altertableleaderaddconstraintFK_leaderforeignkey(myleader)referencesmonitor(sid)实验2.3(1)加入约束U3，令sage的值>=0useschoolaltertableworkeraddconstraintU3check(sage>=0);(2)加入规则R2，确保插入sage值在1~100之间，并绑定sage属性上useschoolgocreaterulerule_sageas@valuebetween1and100goexecsp_bindrulerule_sage,'worker.[sage]';实验2.4(1)触发器T4，使插入sage值比表中最大sage值大useschoolgocreatetriggerT4onworkerforinsertasif(selectsagefrominserted)<=(selectmax(sage)fromworke