Type a report of at least two paragraphs on Entity-Relationship Diagrams.

Entity-Relationship Diagrams DOCTOR Drawing an ERD List the entities that were identified during the systems analysis phase Consider the nature of the relationships that link them A doctor treats a patient TREATS PATIENT FIGURE 9-12 In an entity-relationship diagram, entities are labeled with singular nouns and relationships are labeled with verbs. The relationship is interpreted as a simple English sentence. Entity-Relationship Diagrams (Cont. 1) O Types of Relationships One-to-one relationship: Exists when exactly one of the second entity occurs for each instance of the first entity Abbreviated 1:1 . 1 1 OFFICE MANAGER HEADS OFFICE 1 VEHICLE ID NUMBER ASSIGNED TO VEHICLE FIGURE 9-13 Examples of one-to-one (1:1) relationships. 1 SOCIAL SECURITY ASSIGNED TO PERSON DEPARTMENT HEAD CHAIRS DEPARTMENT