John works as a Database Administrator for DataOneW orld Inc. The company has a SQL Server database.
John wants to insert records in a table where the database is structured in a fixed format. Which of the
following data models will he use to accomplish thetask?

A.
Object relational data model

B.
Entity-Relationship Model

C.
Network data model

D.
Relational model

Explanation:
A relational model uses a collection of tables to represent both data and the relationship between those data.
Every table has multiple columns, and each column has a unique name. A relational model is an example of a
record-based model. Record-based models are so named because the database is structured in a fixed
format. Each table in the database contains recordsof a particular type and each record type defines a fixed
number of fields or attributes. This model is the most widely used data model, and most database systems are
based on this model. This model is at a lower levelof abstraction than the E-R Model.

Answer B is incorrect. The Entity-Relationship Model is a collection of objects called entities and the
relationships between these objects. Entities in a database are known as attributes. A relationship isan
association among several entities. It is a conceptual representation of structured data. Entity- relationship
modeling is a relational schema database modeling method that is used in software engineering to produce a
type of conceptual data model of a system, often a relational database. The logical structure of a database can
be expressed graphically by an E-R diagram, which has the following components:
Rectangle: It represents entity sets.
Ellipse: It represents attributes.
Diamond: It represents relationships among entity sets.
Line: It links attributes to entity sets.
Answer A is incorrect. An object relational data model (ORD) is similar to a relational data model, but with an
object-oriented database model. Objects, classes, and inheritance are directly supported in database schemas
and in the query language.
Answer C is incorrect. The network data model contains logical information such as connectivity relationships
among nodes and links, directions of links, and costs of nodes and links. A node represents an object of
interest and a link represents a relationship between two nodes.