Logical database design

Affiliation: Phuong Hoang
Resolution: Group | Duration: Less than an hour



- Design the logical database for a system and draw the ERD

Learning Objectives

- Be able to identify entities, attributes - Be able to analyze the relationship between entities - Be able to solve many-to-many relationship - Be able to use tools to draw the ERD


A company has a number of employees. The attributes of EMPLOYEE include Employee ID (identifier), Name, Address, and Birthdate. The company also has several projects. Attributes of PROJECT include Project ID (identifier), Project Name, and Start Date. Each employee may be assigned to one or more projects, or may not be assigned to a project. A project must have at least one employee assigned and may have any number of employees assigned. An employee’s billing rate may vary by project, and the company wishes to record the applicable billing rate (Billing Rate) for each employee when assigned to a particular project. Draw an ERD for this case. Do the attribute names in this description follow the guidelines for naming attributes? If not, suggest better names