7.      Prepare an ERD for a real estate firm that lists property for sale. The following describes the organization (NOTE: For most of the information given, it is up to you to determine which are primary keys):

 

·   The firm has a number of sales offices in several states. Each office is identified by a Office_Number and its location.

 

·   Each sales office is assigned one or more employees. Attributes of employee include Employee_ID and Employee_Name. An employee must be assigned to only one sales office.

 

·   For each sales office, there is always one employee assigned to manage that office. An employee may manage only the sales office to which s/he is assigned.

 

·   The firm lists property for sale.  Some of the information they keep track of include Property_ID and location. Components of location include Street, City, State, and Zipcode.

 

·   Each unit of property must be listed with one (and only one) of the sales offices. A sales office may have any number of properties listed, or may have no properties listed.

 

·   Each unit of property has one or more owners, who are identified by Owner_ID and Name. An owner may own one or more units of property.