Entity Relationship Diagram : PDF

Added on - 14 Jun 2021

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1 Entity relationship diagramFigure1: entity relationship diagram2 NormalizationNormalization involves eliminating data redundancy thus enforcing data integrity on a relationaldatabase through restructuring the database through the following stages;First normal form (1NF) - Normalization to first normal form involves removing all repeatinggroups and decomposing the relations in UNF to a set of relations is 1NF.
Second Normal Form (2NF) - Normalization to second normal form involves taking the relationsachieved in normalizing to 1NF and the removing all partial dependencies to obtain relationsthat are in 3NF.Third Normal Form (3NF)- Normalization to third normal form involves taking the relationsobtained in second normal form and eliminating all the transitive dependencies to obtainrelations in 3NF.To describe the normalization process, the first step is to identify relations in UNF.Criminals (Name, address, phoneNO, violentOffenderStatus, probationStatus, aliases)Crime (classifification, dateCHarged, appealStatus, hearingDate, appealCutOffDate,CrimeCodes,criminals,AmountFile,charges,CourtFile,amountPaid,paymentDate,chargesStatus,arrestingOfficers)Appeal(appealFilingDate,appealhearingDate, status, noOfTImesAppeal)Sentencing (startDate, endDate, numberOfViolations, typeOfSentence)PoliceOffice(Name, precint, badgeNumber, phoneContact, Status)Criminals TableUNFCriminals (Name, address, phoneNO, violentOffenderStatus, probationStatus, aliases)1NFThe name attribute is a composite attribute and can be split to firstName and lastName.Criminals (firstName, lastName, address, phoneNO, violentOffenderStatus, probationStatus, aliases)2NFPartial dependencies exist in the relation because there is no unique attribute thus to eliminate thepartial dependencies a primary key criminalNumber is introduced.Criminals (CriminalNumber,FirstName,lastName, address, phoneNO, violentOffenderStatus,probationStatus, aliases)3NFCriminals (CriminalNumber,FirstName,lastName, address, phoneNO, violentOffenderStatus,probationStatus, aliases)CrimeCase TableUNFCrime (classifification, dateCHarged, appealStatus, hearingDate, appealCutOffDate,CrimeCodes,criminals,AmountFile,charges,CourtFile,amountPaid, paymentDate,chargesStatus,arrestingOfficers)1NF
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