1. Advanced Entity Relationship Concepts

2. Advanced Concepts UIDs Intersection Entities Recursive Relationships Roles Subtypes Exclusivity Historical Fan Traps Non transferability

3. Simple Unique Identifier CUSTOMER # * customer num Single attribute Tag the UID with #

4. Compound UID - Attributes MEMBERSHIP # * num # * start date Multiple attributes Members get a new membership each year but keep their membership number.

5. Compound UID - Composite ACCOUNT * num BANK # * num Use a UID bar to indicate that a relationship is part of the entity’s UID Use # to indicate that the attribute is part of the entity’s UID What would you need to know to identify a specific instance of ACCOUNT? #

6. What do you need to know to identify a specific instance of RENTAL ITEM? Rental item requires the rental transaction num and the inventory num Compound UID - Relationships RENTAL ITEM * rental period return date o RENTAL # * transaction num * transaction date COPY # * inventory num * purchase cost

7. Multi-Level Relationship UIDs What would you need to know to identify a specific instance of TICKET? VENUE PLAY # * title PERFORMANCE # * date # * time # * name CUSTOMER # * name TICKET * seat number

8. Multi-Level Relationship UIDs Venue name + Play title + Performance date + Performance time + Customer name VENUE PLAY # * title PERFORMANCE # * date # * time # * name CUSTOMER # * name TICKET * seat number

9. Multiple UIDs badge num payroll num first and last name EMPLOYEE badge num payroll num last name first name # (1) * # (3) * # (2) * *

10. Composition of a UID SUPPLIER # CODE PERSON # NAME # DATE OF BIRTH Example A Example A SUPPLIER TITLE SUPPLIERTITLE distributor of distributed by available as for Example B Example B RENTAL ITEM RENTAL part of composed of # LINE NO Example C Example C

11. Primary Unique Identifier An entity can have several unique identifiers. One may be appointed as the primary unique identifier. Only the Primary UID is shown in the entity relationship diagram.

12. RENTAL ITEM * rental period return date o RENTAL # * transaction num * transaction date COPY # * inventory num * purchase cost RENTAL # * transaction num * transaction date COPY # * inventory num * purchase cost Intersection Entity Note how Crows’ Feet Change!

13. Intersection Entities: Identifying the Problem TITLE SUPPLIER supplied by supplier of In which entity would you store the attribute: purchase price? # * prod code * name # * supplier no * name

14. Intersection Entities CATALOG ITEM available as SUPPLIER supplier of TITLE # * prod code * name # * supplier no * name * purchase price for

15. Unique Identifiers available as CATALOG ITEM SUPPLIER supplier of TITLE # * prod code * name # * supplier no * name * purchase price for CATALOG ITEM available as SUPPLIER supplier of TITLE # * prod code * name # * supplier no * name # * item num * purchase price for OR

16. Modeling Recursive Relationships...and mine...he’s my manager...but I’m HIS manager! EMPLOYEE manager of managed by

17. Modeling Hierarchical Data Company Division Team Department TEAM # name DEPARTMENT # * name DIVISION # * name COMPANY # * name

18. Hierarchies as Recursive Relationships ORGANIZATION ELEMENT made up of within # * name * type TEAM # name DEPARTMENT # * name DIVISION # * name COMPANY # * name

19. Network Structures COMPONENT # * identifier a part of made up of

20. Network Structures COMPONENT # * identifier a part of made up of COMPONENT made up of a part of # * identifier

21. Network Structures COMPONENT made up of a part of # * identifier ASSEMBLY RULE COMPONENT # * identifier COMPONENT # * identifier made up of a part of for o quantity

22. Network Structures COMPONENT ASSEMBLY RULE a part of made up of for o quantity # * identifier

23. Identifying Roles ENROLLMENT STUDENT COURSE SECTION INSTRUCTOR for included in taken by taught by the teacher of * date enrolled * fee # * id * name * location * start date # * id * name * salary COURSE # * code * name for the subject of

24. Modeling Roles for enrolled on ENROLLMENT * date enrolled COURSE # * code * name PERSON # * id * name o salary * fee taught by for COURSE SECTION * location * start date taken by the teacher of included in

25. Subtypes * category * duration O audio TITLE # * * product code title description * GAME MOVIE * category * medium * minimum memory All titles are either movies or games

26. Creating a Subtype In ERD: Drag and drop. or Draw new entity fully within or around the other. In RON: Set Property Type of. or Drag and drop. Select association for dropped entity. Drag and drop. and Select association for dropped entity. Select Associations Type of Sub Entities

27. Exclusive Entities COMPANY id name telephone num supplier num sales contact # * o * * o COPY acquired from the source of the holder of held by MEMBERSHIP * num * start date * expiry date termination # * inventory num o condition o Company in two roles

28. Splitting Entities COMPANY # * * acquired from the source of the holder of held by id name telephone num * OTHER supplier num sales contact * SUPPLIER MEMBERSHIP * num * start date * expiry date termination # COPY * inventory num o condition o Could teacher-student-person be so modeled?

29. Nesting Entities EMPLOYEE SALES REP TELESALES CLERICAL HUMAN RESOURCES CAR driven by authorized to drive Business Rule: only sales reps can drive company cars

30. Nesting Entities AIRCRAFT AIRPLANE GLIDER POWERED AIRPLANE PROP PLANE JET PLANE HELICOPTERHOVERCRAFT OTHER AIRCRAFT

31. Recursive Subtypes ORGANIZATION ELEMENT TYPE ORGANIZATION ELEMENT made up of ORGANIZATION SUBDIVISION within of the classification for

32. Modeling Exclusive Relationships o o MEMBERSHIP COMPANY CUSTOMER the holder of held by the holder of * num * start date * expiry date o termination * name * postal area 0 contact name * num * first name * last name

33. Creating an Arc CATALOG PUBLICATION REVIEW in of in

34. Modeling Exclusivity “We offer membership to individual customers and companies” MEMBERSHIP CUSTOMER COMPANY MEMBERSHIP CUSTOMER COMPANY MEMBERSHIP CUSTOMER COMPANY MEMBER INDIVIDUAL ORGANIZATION

35. Modeling Data over Time APARTMENT # * code * address PERSON # * id * last name * first name rented by the renter of What if you need to hold an apartment’s rental history?

36. Modeling Data over Time APARTMENT # * code * address PERSON # * id * last name * first name rented by RENTAL HISTORY for the renter of for # * from date to date o

37. Modeling Data over Time the employer of employed by COMPANY # * code * name # * id last name * * first name MEMBER

38. Modeling Data over Time COMPANY # * code * name # * id last name * * first name MEMBER # * from date to date o EMPLOYMENT HISTORY ENTRY for employed by the employer of

39. Fan Traps PERSON POSITION COMPANY # * id * last name * first name # * job title job description o # * code * name the holder of held by included in the employer of employed by

40. Fan Traps PERSON POSITION COMPANY # * id * last name * first name # * job title job description o # * code * name employed as held by the subject of the employer for the employer for employed at POSITION HISTORY ORGANIZATION HISTORY COMPANY HISTORY for * start date end date o * start date end date o * start date end date o

41. Resolving Fan Traps PERSON POSITION COMPANY # * id * last name * first name # * job title job description o # * code * name the employer for for EMPLOYMENT HISTORY a party to at as included in * start date end date o #

42. Transferable Relationships DEPARTMENT # * code PERSON # * id * last name * first name works in employs PersonnelFinanceSales Head office

43. Non-Transferable Relationships COMPANY # * * acquired from the source of id name telephone num supplier num sales contact * * SUPPLIER COPY * inventory num o condition OTHER *