Draw an entity relation diagram

Question

Draw an entity relation diagram (ERD) for the following entities. You also need to include attributes indicating primary and foreign keys. Include associative entities if necessary.            

1.    STUDENT, COURSE

2.    EMPLOYEE, PROJECT

3.    PATIENT, PATIENT HISTORY

4.    CELL PHONE PLAN, CUSTOMER

5.    MOVIE, MOVIE HALL

Answer 1

You are practically asked to find the VERB that connects the two concepts and use the right connectors (one-to-one, one-to-many, many-to-many). The rest of the attributes are left to your imagination.

(1) Students <take, register, enroll> Courses; I'd say {one student can enroll in many/different courses} and {one course can have multiple/different students enrolled}, so a many-to-many relation. You can draw the following easily and move on to others (2-3-4-5)

Student (Rectangle on Left)

----------------

studentid (* primary key-PK)

studentName

address, DOB, etc.

Course (Rectangle on Right)

--------------------

courseId (* primary key-PK)

courseName

description, etc.

<Enrol> (Diamond in the middle)

-------------------

studentId (FK) (many-to-many connector to Student)

courseId (FK) (many-to-many connector to Course)