In this article, we will learn how to Configure Many to Many Relationship in Entity Framework core. You can visit the Tutorial Relationships in Entity Framework to learn how to configure one-to-one or one-to-many relationships between entities.
In this tutorial, we will learn how to Configure One to Many relationships in Entity Framework Core. You can use EF Core Conventions, Data Annotations or Fluent API to configure the One to Many relationships.
We are going to look at how to Configure one to one relationship in entity framework core using Convention, Data Annotations & Fluent API.
In relational databases, it is a healthy practice to divide the data between related tables. For Example, the employee working in a particular department. We do not store both the information in the same table but divide them into Employee & Department table. When we divide tables, we also need to specify the relationships between them. For example, if you are looking for an employee working in a particular department, then you need to specify the relationship between employees and the department table. The relationship between these tables is defined using the foreign keys. We then use these relationships to query the database to get the meaningful data.
The HasAlternateKey method creates the Unique constraint for the property in the database. The Primary Key already has Unique Constraint defined, but you can have only one Primary Key in the table. Unique Constraints ensures that no duplicate values are entered in the columns.