Database Models
It is used to show the logical structure of the database, including relationships and constraints which determines how data can store and how can be accessed.
Types of Models
Relational model
Hierarchical database model
Entity-Relationship model
Network model
Object oriented database model
Object relational model
Other database model
No SQL database model
Hierarchical Model
This model is organizing the data in the tree like structure. Hierarchy of the model is tarting from the root data and then it expands in the form of the tree where the child node is added to the parent node.
This model is normally used to represent the sitemap of the website and other databases where we can implement the tree structure to store the data.
Network Model
It is an extension of the hierarchical model. It is same like an Hierarchical model, but the main difference is that, record can have more than one parent. This model replaces the Hirearchical database model with the Graph.
Example:
Entity-Relationship Model
The E-R data model is high level model diagram. In this model, to represent the real world problem we use pictorial representation of the database. It is very easy for developers to understand the way of the database and its records and relationship between the tables.
In E-R diagram table will be considered as the Entity. By using we represents the relationship between two tables.
Relational Model
In this model, the data is organised 2-Dimensional tables and the relationship between two tables are maintained by storing the common field between the tables.
It was introduced in 1970 by E.F. Codd, and since then it is the most popular data model in the database. Now the only database model which is used around the world to store the data in the database.
The basic structure of this model is tables, in which form all the data of the tables are stored using columns, which represents the field of the record and single row considered as the record.
