This document discusses relational database design concepts including: - Entity Relationship Diagrams (ERDs) that model entities and relationships between entities. - Case studies that involve merging user views into a global logical data model. - Tables, relationships, and diagrams for a StayHome database system. - Normalization concepts including normal forms, data redundancy, and update anomalies. - Logical and physical database design including implementing a physical MySQL database.

1. Relational Database
Design for Information System

2. Entity Relationship Diagram
 A well designed ERD automatically
delivers a reliable relational logical
database
ERD has Entities and Relationships
between Entities
Extracted from the Data requirements …
Nouns are Entities and Verbs are
Relationships

3. Case Study
 All users views are merged - View integration
approach
 Merge local logical data models into global model
 Check global logical data model
 Check for future growth
 Review global logical data model with users

4. ER model for the Business user views of
StayHome.

5. Tables for the Business user views of StayHome

6. diagram for the
StayHome database
system

7. Table structures for the global logical data model of
StayHome.

8. Staff Manages Branch
(1:1) relationship: (a) individual
examples

9. Staff Manages Branch
(1:1) relationship:(b) multiplicity

10. Branch Has Staff (1:*) relationship:
(a) individual examples;

11. Branch Has Staff (1:*) relationship:
(b) multiplicity.

12. Superclasses and subclasses
 Superclass An entity that includes one or more
distinct groupings of its occurrences, which require to
be represented in a data model.
 Subclass A distinct grouping of occurrences of an
entity, which require to be represented in a data
model.
 Participation constraint Determines whether every
occurrence in the superclass must participate as a
member of a subclass.
 Disjoint constraint Describes the relationship
between members of the subclasses and indicates
whether it’s possible for a member of a superclass to
be a member of one, or more than one, subclass.

15. Normalization
 A technique for producing a set of tables with
desirable properties that support the requirements
of a user or company.
 In 1972, Dr E.F. Codd developed the technique of
normalization to support the design of databases
based on the relational model.
 Normalization is often performed as a series of
tests on a table to determine whether it satisfies or
violates the rules for a given normal form. T
 There are several normal forms, although the most
commonly used ones are called first normal form
(1NF), second normal form (2NF), and third normal
form (3NF).
 All these normal forms are based on rules about

16. Data redundancy and update
anomalies
 Redundant data: the details of a branch are repeated for
every member of staff located at that branch. In contrast, the
details of each branch appear only once in the Branch table
and only the branch number (branchNo) is repeated in the
Staff table, to represent where each member of staff is
located.
 Tables that have redundant data may have problems called
update anomalies, which are classified as insertion,

17. Normal Forms
 First normal form (1NF) A table in which the
intersection of every column
 Second normal form (2NF) A table that is
already in 1NF and in which the values in each
non-primary-key column can be worked out from
the values in all the columns that make up the
primary key. and record contains only one value.
 Third normal form (3NF) A table that is already
in 1NF and 2NF, and in which the values in all
non-primary-key columns can be worked out from
only the primary key column(s) and no other
columns.

18. Logical Design

20. Physical Design

21. Exercise - Individual
 Implement physical database design in MySQL
(Use Wamp or Xamp Server)
 Physical Database Design for the selected
scenario
 Mission Statement till populated database
 Logical Database size should be about similar to
database size in book
 Wednesday 27-03-2022