数据库应用技术_在线作业_a（application of database technology _ online operation _a）

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1、数据库应用技术_在线作业_a（Applicationofdatabasetechnology_onlineoperation_a）OneTheabbreviationofdatamanipulationlanguageis().DMLDDLDBDBASubjectpoints:5Userscore:5Useranswer:DMLKnowledgepoints:1.1.3database,databasemanagementsystem,databasesystem--------------------------------------------------------------

2、------------------TwoE-Rdiagramsprovidemethodsforrepresentingentities,attributes,andconnections,wheretheentitytypeis().EllipsediamondrectangleUndirectededgeSubjectpoints:5Userscore:5Useranswer:rectangleKnowledgepoint:1.1.4datamodel-----------------------------------------------------------------

3、---------------ThreeThephysicalstructureandstoragepatternofthedataaredescribed.PatternSubpatternExternalmodeInternalmodelSubjectpoints:5Userscore:5Useranswer:internalmodelKnowledgepoint:thearchitectureof1.1.5databasesystem--------------------------------------------------------------------------

4、------FourInrelationaldatabases,theconstraintsthatcannotbeusedtorefertotuplesthatarenotpresentinthemaintablefromthetableare().DefaultconstraintReferentialintegrityrulesEntityintegrityrulesUniquenessconstraintSubjectpoints:5Userscore:5Useranswers:referentialintegrityrulesKnowledgepoint:1.2.1relat

5、ionmodel--------------------------------------------------------------------------------FiveX=Y,whichiscalledtrivialfunctionaldependencywhenthefollowingconditionsareestablished.XY=fXYXY=fYXSubjectpoints:5Userscore:5Answer:YXusersKnowledgepoints:1.2.2relationaldatatheory--------------------------

6、------------------------------------------------------SixThetransformationfromE-Rmodeltorelationaldatabaseindatabasedesigniscarriedoutin()phase.conceptualdesignphysicaldesignlogicdesignrequirementanalysisSubjectpoints:5Userscore:5Useranswer:LogicDesignKnowledgepoint:thetaskof1.3.2requirementanal

7、ysis--------------------------------------------------------------------------------SevenWhentheE-Rmodelistransformedintoarelationaldatabase,thecodeoftherelationalschemaofthem:nconnectiontransformationshouldbe().Thecombinati