Business Rules Implicitly Indicated
Added on - 16 Sep 2019
Chapter - 225(a). Business Rules Explicitly stated1.A university have more than one college.2.Each college has 4 terms.3.Each term can have one or more than one course.4.Instructor can teaches one or more than one course.Business Rules Implicitly indicated1.Course# and course name should be unique.2.Instructor teaches in 0 to 4 terms.3.In a term the combination of instructor and course should be unique.25(b). To complete this data model there should be module of student,which contain studentID, student name, student address and college that isbeing chosen by him.26. There are two users that are client and agent and relation betweenthem is policy. A client buys the policy from the agent and can buy manypolicy with different agent and relation between client and policy is one tomany. A agent can sell the policy to a client and can sell many policy andrelation between aget and policy is zero to many that an agent is related toany policy is not mandatory
Chapter - 36. The business rule that is missing is the the customer module. Thereshould be entity of customer who can book a reservation. A customer canbook a flight reservation but the combination of reservation and flight for aparticular customer should be unique.7. (a) Weak Entity - ServiceStrong Entity - AIRCRAFT, TECHNICIAN, TRUCK, FLIGHT,RESERVATIONUnique identifier of entityAIRCRAFT - TailTECHNICIAN - SSTRUCK - License PlateFLIGHT - FlightIDRESERVATION - Reserv ID(b) Partial key - Tail in entity AIRCRAFT.(c) Optional attributesHours in Entity SERVICETenure in Entity TECHNICIANMulti- valued attributeSpeciality in entity TECHNICIAN(d) Derived attributes -SERVICE is derived from AIRCRAFTRESERVATION is derived from flight(e) Recursive relationship is in FLIGHT entityBinary relationship is between FLIGHT and RESERVATION,And SERVICE and TECHNICIAN
(f) Partial participations among entities areAIRCRAFT and SERVICEFLIGHT and RESERVATIONTotal participation among entities areAIRCRAFT and FLIGHTSERVICE and TECHNICIANTECHNICIAN and TRUCK(g) 1:1 cardinality ratio means there should be unique foreign key inboth entity1:n cardinality ratio means in one entity there should be uniqueforeign key and in other there can be repetition of foreign key.N:m cardinality ratio means there can be many number of foreign keyin both entity.(h) Diamond has a single line, the relationship only includes strongentity sets.Diamond has double lines, the relationship includes a weak entity set.(j) It is the optional clause.