Model Relationships Read the relationships. Write the relationship sentences for this E-R diagram. ORDER number type ITEM number description issued for bought via stored in originated by the originator of the repository for CUSTOMER first name last name WAREHOUSE id address

Model Relationships – Solution Each ORDER must be issued for one or more ITEMs. Each ITEM may be bought via one or more ORDERs. Each ORDER must be originated by one and only one CUSTOMER. Each CUSTOMER may be the originator of one or more ORDERs. Each ITEM must be stored in one and only one WAREHOUSE. Each WAREHOUSE may be the repository for one or more ITEMs.

Modeling Exercise Draw an Entity-Relationship Diagram. Draw an Entity-Relationship diagram to represent the following: a Each EMPLOYEE must be assigned to one and only DEPARTMENT. b Each DEPARTMENT may be responsible for one or more EMPLOYEEs. c Each EMPLOYEE may be assigned to one or more ACTIVITIES. d Each ACTIVITY may be performed by one or more EMPLOYEEs.

Modeling Exercise Solution DEPARTMENT EMPLOYEE assigned to responsible for assigned to performed by ACTIVITY

Discussion Pair students and have them brainstorm on the following questions: What are all the categories to which you belong or would like to? Be creative. Use all applicable labels that apply (and some that don't!) i.e. student, child, young adult, city, state, clerk, athlete, musician, sci-fi reader, prankster, etc. Have students write 5 minutes in their journal on the question "How can you scale down your understanding of 'school' to entities? What categories have significance? (this could be a loaded question!) Facilitate discussion of journal responses.