Single-Valued and Multi-Valued Attributes
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In this class, we will understand Single-Valued and Multi-Valued Attributes.
We have already discussed the concept of attributes, simple and composite attributes.
Table of Contents
Single-Valued and Multi-Valued Attributes
In this class, we will discuss other kinds of attributes.
Example
To understand this, we will consider department entity type with name, number, and location attributes as shown below.
Before proceeding further, try to take a guess which among those is a single-valued or multi-valued attribute.
The name attribute is single-valued because no department will have two names.
Similarly, the number attribute is single-valued as no department will have two numbers.
But the locations attribute is multi-valued because a department can have multiple locations.
For example, an administrative department may have its location in Mumbai and Delhi.
ER-Diagram Representation
We will represent the multi-valued attributes in double ovals, as shown below.
