Single-Valued Attribute
The attribute which takes up only a single value for each entity instance is a single-valued attribute.
Example: The age of a student, Aadhar card number.
Types of Attributes in ER Model
In a Database Management System (DBMS), an attribute is a property or characteristic of an entity that is used to describe an entity. Essentially, it is a column in a table that holds data values. An entity may contain any number of attributes. One of the attributes is considered as the primary key. In an Entity-Relation model, attributes are represented in an elliptical shape.
Example: Student has attributes like name, age, roll number, and many more. To uniquely identify the student, we use the primary key as a roll number as it is not repeated. Attributes can also be subdivided into another set of attributes. Attributes help define and organize the data, making it easier to retrieve and manipulate information within the database. In this article, we are going to discuss about different types of attributes in detail.