insert for many to many relation in entity framework

Question

User87195929 posted

hi team.

i am unable to insert the many to many relation useing

navigation property for 2 table..

if i have 2 table like student and hobbies.

studenthobbies contain primaray key of 2 table.

how can i insert via navigation property for studenthobbies table...or give some link 

Answer 1

User475983607 posted

The community cannot provide guidance without your code.   Is there anyway you can share sample code that illustrates the problem?

Otherwise, inserting records in Entity Framework is covered in the official documentation.  It does not matter if you are inserting one record or many records the code is same.

https://docs.microsoft.com/en-us/ef/core/saving/basic

Answer 2

User1535942433 posted

Hi siddangoud,

According to your description,I think you need  insert data in tables that has a relationship many-to-many.

You need to map entities add navigation property to represent that relation.And then you could insert data into it.

More details,you could refer to below article:

https://www.codeproject.com/Tips/893609/CRUD-Many-to-Many-Entity-Framework

Best regards,

Yijing Sun

Answer 3

User87195929 posted

Hi

i am ref this link

https://www.codeproject.com/Tips/893609/CRUD-Many-to-Many-Entity-Framework

but in insert method

for naviagation property is not working for insert

my question samle like

https://forums.asp.net/t/2152629.aspx?Need+help+with+MVC+Create+Edit+form+for+many+to+many+relationships

Answer 4

User475983607 posted

Saving data is trivial.  Share your code so we can see what you are doing wrong. 

Answer 5

User1535942433 posted

Hi siddangoud,

Hi

i am ref this link

https://www.codeproject.com/Tips/893609/CRUD-Many-to-Many-Entity-Framework

but in insert method

for naviagation property is not working for insert

my question samle like

https://forums.asp.net/t/2152629.aspx?Need+help+with+MVC+Create+Edit+form+for+many+to+many+relationships

According to your description,I don't understand your requirement clearly.You need many To many relationships in Entity Framework Core?If you need this,you could use  the Fluent API. If not,you could post your codes and tell us more details of requirements to us.It will help us to solve your problems.

More details,you could refer to below article:

https://www.learnentityframeworkcore.com/configuration/many-to-many-relationship-configuration

Best regards,

Yijing Sun

Answer 6

User-1044770503 posted

Hi,

Check the following page with the sample code to create, read, update and delete records in EF many to many relationships

https://mycodingtips.com/2021/3/16/sample-code-to-create-read-update-and-delete-crud-records-ef-core-many-to-many-relationships

Answer 7

User503812343 posted

you will have to configure model entities OnModelCreating event of DBContext

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<DeptEmployee>()
            .HasKey(de => new { de.EmployeeId, de.DepartmentId });
}

public DbSet<Employee> Employees { get; set; }
        
public DbSet<Department> Departments { get; set; }
public DbSet<DeptEmployee> DeptEmployees { get; set; }

 

for more information see https://geeksarray.com/blog/how-to-configure-entity-relationships-using-fluent-api-in-entity-framework