Contents
- 1 How do I create a many to many relationship in entity Framework?
- 2 Can you have a many to many relationship in an ERD?
- 3 How do I remove a one-to-many relationship in Entity Framework?
- 4 How are many to many relationships represented in Entity Framework Core?
- 5 Are there default conventions in Entity Framework Core?
- 6 How to configure foreign keys in joining entity?
How do I create a many to many relationship in entity Framework?
To add a many-to-many relationship in EF Core you need to:
- Create a linking entity class that has the foreign keys(s) of the two entities you want to form a many-to-many link between.
- It is efficient (but not necessary) to make these two foreign keys into the composite primary key.
Can you have a many to many relationship in an ERD?
A many-to-many relationship refers to the relationship between two entities X and Y in which X may be linked to many instances of Y and vice versa. The figure below shows an example of a many-to-many relationship. Note that a many-to-many relationship is split into a pair of one-to-many relationships in a physical ERD.
How do you set relationships in EF core?
The easiest way to configure a one-to-many relationship is by convention. EF Core will create a relationship if an entity contains a navigation property. Therefore, the minimum required for a relationship is the presence of a navigation property in the principal entity: public class Author.
How do I remove a one-to-many relationship in Entity Framework?
Cascade delete automatically deletes dependent records or sets null to ForeignKey columns when the parent record is deleted in the database. Cascade delete is enabled by default in Entity Framework for all types of relationships such as one-to-one, one-to-many and many-to-many.
How are many to many relationships represented in Entity Framework Core?
The many-to-many relationship in the database is represented by a joining table which includes the foreign keys of both tables. Also, these foreign keys are composite primary keys. There are no default conventions available in Entity Framework Core which automatically configure a many-to-many relationship. You must configure it using Fluent API.
How are many to many relationships represented in a database?
The many-to-many relationship in the database is represented by a joining table which includes the foreign keys of both tables. Also, these foreign keys are composite primary keys.
Are there default conventions in Entity Framework Core?
There are no default conventions available in Entity Framework Core which automatically configure a many-to-many relationship. You must configure it using Fluent API.
How to configure foreign keys in joining entity?
Configure both the foreign keys in the joining entity as a composite key using Fluent API. So, first of all, define the joining entity StudentCourse, as shown below.