DEV Community

Sardar Mudassar Ali Khan
Sardar Mudassar Ali Khan

Posted on

What is an entity in the Entity Framework with Examples?

In the context of Entity Framework, an entity refers to a class that represents a table in a relational database. It is a fundamental concept in the Object-Relational Mapping (ORM) provided by Entity Framework, which allows developers to interact with the database using objects and their relationships, rather than writing raw SQL queries.

An entity typically corresponds to a row in a database table, and each property of the entity represents a column in that table. The relationships between entities are modeled through navigation properties, which define associations between tables.

Here's an example to illustrate the concept of entities in Entity Framework:

Let's say we have a database with two tables: "Customers" and "Orders". We can define two entity classes in our application to represent these tables:

public class Customer
    public int CustomerId { get; set; }
    public string Name { get; set; }
    public ICollection<Order> Orders { get; set; }

public class Order
    public int OrderId { get; set; }
    public DateTime OrderDate { get; set; }
    public Customer Customer { get; set; }
Enter fullscreen mode Exit fullscreen mode

In this example, the Customer class represents the "Customers" table, and the Order class represents the "Orders" table. Each property in these classes corresponds to a column in the respective table. The CustomerId property in the Customer class, for example, maps to the "CustomerId" column in the "Customers" table.

The ICollection<Order> Orders property in the Customer class represents a one-to-many relationship between customers and orders. It allows us to navigate from a customer to their associated orders.

By using Entity Framework, we can perform operations such as querying, inserting, updating, and deleting data in the database using these entity classes, without having to write explicit SQL statements. Entity Framework handles the mapping between the entities and the database tables, allowing us to work with objects in a more intuitive manner.

Note that this is a simplified example to illustrate the concept of entities in Entity Framework. In a real-world application, you would typically have more complex entity models with additional properties and relationships.

Top comments (0)