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databases in this end user’s Entity-Relationship model
utilisation category are Microsoft Entity-relationship (ER) modelling is a
Access and File MakerPro. best practice for producing well-designed

(b) Popular open-source DBMSs for databases. It depicts the structure of
organisations: The popular and a relational database allowing you to Chapter Eight: Databases and Database Management Systems
FOR ONLINE READING ONLY
most used relational database understand the data and how it shares
in this category is MySQL and information.
PostgreSQL.
(c) Popular proprietary DBMSs for Elements of the entity-relationship model
organisations: The popular and An ER data model’s main elements involve
most used relational databases entities, attributes, and relationships, as
in this category are Microsoft depicted in Figure 8.14, with the example
SQL Server, Oracle, IBM-DB2 from a student database involving how each
and recently AWS - Amazon element is diagrammatically represented.
Relational Database Service
(Amazon RDS), which makes it
easy to set up, operate, and scale Student_ID Course_ID
a relational database in the cloud.
Student Takes Course

Exercise 8.3
Age Credits
1. Identify two related entities
in your school students’
organisation and determine Attribute Relationship Entity
three possible attributes for
each. Create both tables with Figure 8.14: A sample of entities, attributes, and
three tuples for each and show relationships from a student
how they relate.

2. In the tables you have created Entity: An entity is an object representing
in question (2), identify the things from the real world. An entity contains
primary key, candidate key, a set of attributes, each with values.
alternate key and foreign key. Attribute: The attribute is the characteristics
Also, determine the domain or properties of an entity based on the data
for each attribute that was type. Each column represents an attribute that
identified. stores the value of an entity characteristic.
3. Differentiate between selection
and projection in an RDBMS Relationships: Relationships define how
while giving examples. entities are related to each other; and how they
share information in the database. This is done

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Student’s Book Form Five

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