1. ER Diagram Examples 2 Fall 2015 Dr. Abdullah Almutairi
ISC321 Database Systems I
ER Diagram Examples 2
Fall 2015
Dr. Abdullah Almutairi

2. Problem 1
A laboratory has several chemists who work on one or more projects. Chemists may also use certain kinds of equipment on each project. Attributes of CHEMIST include Employee_ID (identifier), Name, and Phone_no.
Attributes of PROJECT include Project_ID (identifier) and Start_Date.
Attributes of EQUIPMENT include Serial_no. and Cost.
The organization wants to record Assign_Date – that is, the date when a give equipment item was assigned to a particular chemist working on a specified project.
A chemist must be assigned to at least one project and one equipment item.
A given piece of equipment need not be assigned, and a given project need not be assigned either a chemist nor a piece of equipment.

3. Problem 2
You’ve been hired by a law firm to construct a database based upon the following business rules. Create an ERD that accurately depicts this situation. Clearly state any assumptions you made.
An ATTORNEY is retained by one or more CLIENTS for each CASE.
Attributes of ATTORNEY are: Attorney_ID, Name, Address, City, State, Zip_Code, Speciality (may be more than one), Bar (may be more than one).
A CLIENT may have more than one ATTORNEY for each CASE.
Attributes of CLIENT are Client_ID, Name, Address, City, State, Zip_Code, Telephone, Date_of_Birth.
A CLIENT may have more than one CASE.
Attributes of CASE are Case_ID, Case_Description, and Case_Type.
An ATTORNEY may have more than one CASE.
Each CASE is assigned to one and only one COURT.
Attributes of COURT are Court_ID, Court_Name, City, State, and Zip_Code.
Each COURT has one or more JUDGES.
Attribtues of JUDGE are Judge_ID, Name and Years_In_Practice.
Each JUDGE is assigned to exactly one court.