Data Models in database
What are Data Models in the database?
A Data Model is a collection of conceptual tools for describing the data, data relationship, data semantics, and consistency constraints. It tells us how the data is connected to each other logically in the database.
Categories of the data model:
There are four types of data models in the database:
Relational Model:
The relational model is one of the most usable models among the Record Based models and it is the most modern model. It models a database as a collection of tables to represent the data and the relationship amongst the data. A relation is a table with rows and columns and each relationship has a number of columns called attributes of the relation. So, a table can have any number of rows and each row represents an instance of the relation. It is used for data storage and processing therefore, we can access the data easily with the help of this model. We keep the data in the table form like the below example so you can have a clear view.
STUDENT TABLE:
| Student_rollno | Student_name | Branch | Semester | Address |
Entity-Relationship Data Model:
It describes data as entities, attributes, and relationships. An entity refers to a real-world ‘object’ or ‘concept’ that can be distinguishable from other objects and concepts in the real world. A person, a payment, a bank account are all different examples of entities. An entity has a set of properties, known as attributes. If more than two entities have the same types of attributes then they are called entity sets. Below the picture has attached for an example of an entity-relationship data model.
Object-Based Data Model:
The object-Based data model is also called the conceptual data model. It doesn’t depend upon the software and hardware so it is independent of the hardware and software of the computer. We represent entities, attributes, and relationships in this data model. It is easily understandable and business users who have no technical knowledge can also use it easily. It is a conceptual data model, so it describes the data on the conceptual and view level.
Semi-Structured Data Model:
The semi-structured data model is the data model, where there is no separation between the data and the schema. In this model, the information does not reside in a relational database. It has some organizational properties which make it easier to analyze. We can store it in the relational database with some processes but it is not necessary that we can always store them in a relational database because in some cases it is very hard to store semi-structured data. There are some examples of semi-structured data i.e. XML data, JavaScript Object Notation(JSON), HTML files etc.
Also, read Database languages in DBMS
