Attributes are the properties which describe an entity.
Example
The attributes of student entity are as follows −
Roll number
Name
Branch
Age
The different types of attributes are as follows −
It can be divided into smaller sub parts, each sub part can form an independent attribute.
For example −
Name FirstName MiddelName LastName
Attributes that cannot be further subdivided are called atomic attributes.
For example −
Phone number PIN code
Attributes having a single value for a particular item is called a single valued attribute.
For example: Room Number
Attribute having a set of values for a single entity is called a multi-valued attribute.
For example −
e-mail Tel.No Hobbies
When one attribute value is derived from the other is called a derived attribute.
For example: Age can be derived from date of birth, where,
Age is the derived attribute.
DOB is the stored attribute.
Nesting of composite and multi-valued attributes forms a complex attribute.
For example
If a person has more than one house and each house has more than one phone. Then, that attribute phone is represented as a complex attribute.