ER diagram with a case scenario

1. Case Scenario:
Mary is a small library owner, she has been
recording issues by an out of date card system.
She wants to move into the digital world and
wants you to change her card system into an
access database…
She needs to store information on clients, Issues
and books. Books have their own ISBN numbers,
but she also wants her own unique numbering
system per book.

2. First Step: Create the borrowers table
MemberID (PK)
FirstName
LastName
Phone Number
Mobile Number
Email Address
Address
City
Postal Code
MemberID created in
order to make
uniqueness

3. 2nd Step: Create the Books table
MemberID (PK)
FirstName
LastName
Phone Number
Mobile Number
Email Address
Address
City
Postal Code
BookID (PK)
Author
Title
Edition
ISBN
Condition
Gender
BookID created in order
to make uniqueness
Gender is wrong
because books don’t
have a gender

4. Problem: !!!!!!!
MemberID (PK)
FirstName
LastName
Phone Number
Mobile Number
Email Address
Address
City
Postal Code
BookID (PK)
Author
Title
Edition
ISBN
Condition
A Member can hire
many books and a
book can be issued
by many members

5. 3rd Step: Create the issues table to resolve
MemberID (PK)
FirstName
LastName
Phone Number
Mobile Number
Email Address
Address
City
Postal Code
BookID (PK)
Author
Title
Edition
ISBN
Condition
IssuesID (PK)
DateIssued
DateReturned
MemberID (FK)
BookID (FK)
* FK = Foreign key and is used to link
tables together

6. 4th Step: Declare the relationships
MemberID (PK)
FirstName
LastName
Phone Number
Mobile Number
Email Address
Address
City
Postal Code
BookID (PK)
Author
Title
Edition
ISBN
Condition
IssuesID (PK)
DateIssued
DateReturned
MemberID (FK)
BookID (FK)
* One Member can have many issues,
an issue is only made by one member
1
∞
1
* One book can be issued many
times, each issue contains only one
book
∞