GETTINGTFAMILIARTWITHTTERMS 1.

TERTMODELT:TTheTentityTrelationshipTdataTmodelTonTaTperceptionTofTaTrealTworldTthatTconsistsTofTaTcollectionTofTbasicTobjectsTcalledTentitiesTandTofTrelationshipsTamongTthem.TThisTrepresentsTtheTlogicalTstructureTofTanTdatabase.2.

Best services for writing your paper according to Trustpilot

Premium Partner
From $18.00 per page
4,8 / 5
4,80
Writers Experience
4,80
Delivery
4,90
Support
4,70
Price
Recommended Service
From $13.90 per page
4,6 / 5
4,70
Writers Experience
4,70
Delivery
4,60
Support
4,60
Price
From $20.00 per page
4,5 / 5
4,80
Writers Experience
4,50
Delivery
4,40
Support
4,10
Price
* All Partners were chosen among 50+ writing services by our Customer Satisfaction Team

TENTITIEST:TAnTentityTisTaTthingTinTtheTrealTworldTthatTisTdistinguishableTfromTallTotherTobjects.Can be person, place, event, object, concept in the real worldCan be physical object or abstractionEx: “John”, “CSE305″3.TATTRIBUTEST:TAnTentityTisTrepresentedTbyTaTsTetTofTattributes.TTheseTareTdescriptiveTpropertiesTpossessedTbyTeachTmemberTofTtheTentityTset. 4.

TRELATIONSHIPTSETST:TATrelationshipTsetTisTaTsetTofTrelationshipsTofTtheTsameTtype.5.TCONSTRAINTST:TAnTE-RTenterpriseTschemaTmayTdefineTcertainTconstraintsTtoTwhichTtheTdatabaseTmustTconform.6.TENTITYTSETST:TATsuperkeyTisTaTsetTofToneTorTmoreTattributesTthatTtakenTcollectively,allowTusTtoTidentifyTuniquelyTanTentityTinTanTentityTset.

7.TN-ARYTRELATIONSHIPST:TGenerallyTtheTrelationshipsTareTbinary,TsometimesTtheTdatabaseThasTmoreTthanToneTentity,TsoTtheyThaveTtertiaryTorTn-aryTrelationships.TThisTparticularTmodelTisTaTtertiaryTrelationshipT(threeTentityTsets).

8.TMAPPINGTCARDINALITIEST:?TONE-TO-ONET:TEveryTentityTinTeachTofTtheTtwoTentityTsetTareTatTmostTrelatedTtoToneTentityTeach.?TONE-TO-MANY:TAnTentityTinTcustomerTisTassociatedTwithTaTnumberTofTentitiesTinTorder.ButTAnyTentityTinTorderTcanThaveTatTmostToneTentityTinTcustomer.?TMANY-TO-ONE:TAnTentityTinTsetTATisTassociatedTwithTatTmostToneTentityTinTB.TButTAnyTentityTinTBTcanTbeTassociatedTwithTaTnumberTofTentitiesTinTA.

?TMANY-TO-MANY:TAnTentityTinTproductTcanTbeTassociatedTwithTaTnumberTofTentitiesTinTorderTandTviceTversaTisTalsoTtrue.9.TANTE-RTDIAGRAMTCOMPOSESTOFTTHESETMAJORTCOMPONENTST:T?TRECTANGLEST-TEntityTsetsT(TCUSTOMER,TPRODUCT,TORDER)?TELLIPSEST-AttributesT(C-ID,FIRSTNAME,LASTNAME,QUANTITY,TSTREET,STATE,ETC..TFromTtheTexample)?TDIAMONDS-TRelationshipTsetsT(customer-PLACES-order.

Torder-LISTS-products)T?TLINES-TlinkingTentityTsets,TattributesTandTrelationshipTsets.