Cardinality constraints a rule that specifies the

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RUNNINGHEAD: IST 7000 DATA MANAGEMENT WEK 2 ASSIGNMENTSoIf one or more, then mandatoryMaximum CardinalityExamples of cardinality constraints area)Mandatory cardinalitiesb)One optional, one mandatoryc)Optional cardinalitiesMandatory Cardinalities
RUNNINGHEAD: IST 7000 DATA MANAGEMENT WEK 2 ASSIGNMENTSPATIENT Has Recorded PATIENT HISTORY. Each patient has one or more patient histories. (The initial patient visit is always recorded as an instance of PATIENT HISTORY.) Each instanceof PATIENT HISTORY “belongs to” exactly one PATIENT.One optional, one mandatoryEMPLOYEE Is Assigned To PROJECT . Each PROJECT has at least one EMPLOYEE assignedto it. (Some projects have more than one.) Each EMPLOYEE may or (optionally) may not be assigned to any existing PROJECT (e.g., employee Pete), or may be assigned to one or more PROJECTs.Optional cardinalities
RUNNINGHEAD: IST 7000 DATA MANAGEMENT WEK 2 ASSIGNMENTS
6.What is the degree of a relationship? List the three types of relationship degrees described in the chapter and give an example of each.
RUNNINGHEAD: IST 7000 DATA MANAGEMENT WEK 2 ASSIGNMENTSCardinality of RelationshipOne-to-OneEach entity in the relationship will have exactly one related entityOne-to-ManyAn entity on one side of the relationship can have many related entities, but an entity on the other side will have a maximum of one related entityMany-to-ManyEntities on both sides of the relationship can have many related entities on theother sideExamples of relationships of different degreesa) Unary relationshipsb) Binary Relationships
RUNNINGHEAD: IST 7000 DATA MANAGEMENT WEK 2 ASSIGNMENTS

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