What is entity in database

Also sometimes it can be difficult to decide whether there is a need to create entity table or add several properties to the entity itself. If each contact has only one address, then these properties can belong to entity, while if your contact can have several addresses, these properties should belong to entity table. Entity workflow is a kind of an entity lifecycle which consists of states, transitions and reasons why entity transits from one state to another.

Also workflow may have actions performed by CentriQS automatically when transition between the states takes place. Entity settings are system attributes of the entity. Some of them can be set when new entity is created and cannot be modified after the changes are committed, others can be edited and changed at any time later. If your database will have several entities that start with the same letter, it is better to build code prefix from letters. The reason is simple, just like the keyboards, we have to retrieve the data from the database and each of them should have a unique value that can be used to differentiate between two different data.

So, when an object becomes uniquely identifiable we can call it an entity. Now, let's see in more depth what is an entity and what are entity types and entity sets. An entity is a real-world thing which can be distinctly identified like a person, place or a concept. It is an object which is distinguishable from others. If we cannot distinguish it from others then it is an object but not an entity. An entity can be of two types:. Tangible Entity: Tangible Entities are those entities which exist in the real world physically.

Example: Person, car, etc. Intangible Entity: Intangible Entities are those entities which exist only logically and have no physical existence.

Example: Bank Account, etc. The entity type is a collection of the entity having similar attributes. In the above Student table example, we have each row as an entity and they are having common attributes i.

The table below shows how the data of different entities different students are stored. Strong Entity Type: Strong entity are those entity types which has a key attribute.

The primary key helps in identifying each entity uniquely. Database Analysis. Database Design. Extended DB Features. Oracle SQL Extensions. Step 1 : The first step in the logical design stage of the DBLC database life cycle is to create a conceptual model. This involves converting business objects and their characteristics identified during requirements analysis into the language of entities and attributes for use in an ER diagram.

An entity is a business object and can be either tangible such as a person or an item or intangible such as an event or a reservation.