Entity Types and Entity Sets
An entity type is defined as a collection of entities, which share a common definition in terms of their attributes. Each entity type is assigned a name for its subsequent identification. The attributes of entity type are used to describe it in the database. The value of attributes of an entity belonging to entity type are known as “Entity Instance”.
An entity set is a collection of all entity instances of a particular entity type. An entity type is described by a set of attributes called “Schema”. The set of entities pertaining to a particular entity type share the same set of attributes. The collection of entities of a particular entity type is grouped into entity set, called the extension of the entity type.
For example: Entity type: Accounts
Structure of entity type:
Entity set: Collection of entity instances of an entity
Extension or Instances of entity type:
Code |
Name |
Type |
71011 |
Captial Account |
4 |
221019 |
Sunil & Co. |
4 |
632001 |
Bank Account |
3 |