1. Entity Relationship Diagrams (ERDs)

2. Entity Relationship Diagram (ERD) documentation technique to represent relationship between entities in system. Think of entities as “nouns” – nouns on which a company would want to track information. A few examples: Vehicles Accounts Receivable Customers Vendors 2

3. Entity Relationship Diagram (ERD) Think of the relationship as a “verb” The verb connects (relates) one entity to another. A few examples: Receive Assign Prepare Send 3

4. 4 Cardinality between entities represents the numerical mapping between entities: one-to-one one-to-many many-to-many Depends on business rules !!

5. Sales- person Car Customer is assigned EntityRelationshipEntity 1 1 Company A

6. Sales- person Car Customer is assigned EntityRelationshipEntity M1 Company B

7. 7 Customer Order places EntityRelationshipEntity M 1 This cardinality is probably true for most businesses.

8. 8 VendorInventory supplies EntityRelationshipEntity M M This cardinality would depend on the business.

9. ERD – Expenditure Cycle

10. 10 Describe the business rules represented by the cardinalities in the ERD. P.O. REC. RPT. INVENTORY VENDOR M M 1 M 1 M M M 1 1

11. 11 Add 3 attributes for each entity. P.O. REC. RPT. INVENTORY VENDOR M M 1 M 1 M M M 1 1

12. 12 3 attributes for each entity. P.O. REC. RPT. INVENTORY VENDOR M M 1 M 1 M M M 1 1

13. 13 Modify the ERD, based on the following information: The Vendor sends an invoice for each shipment. The invoice is matched to the RR; a Cash Disbursement (CD) is prepared for each invoice. 13 P.O. REC. RPT. INVENTORY VENDOR M M 1 M 1 M M M 1 1

14. 14 P.O. REC. RPT. INVENTORY VENDOR M M 1 M 1 M M M 1 1

15. 15 P.O. REC. RPT. INVENTORY VENDOR M M 1 M 1 M M M 1 1 Add 3 attributes for each new entity.

16. 16