In entity framework core, how we can set relationship for a table, when two fields is mapping to primary key of the another table

Question

In entity framework core, how we can set relationship for a table, when two fields is mapping to primary key of the another table. For example I have two table namely Users & CashBox.

Users Table

Field	Value
UserId	int
UserName	string

CashBox Table

Field	Value
CashBoxId	int
ActivatedBy	int
DeactivatedBy	int

In this case, activatedby & deactivatedby has to be linked with user table. Need to know who activated cashbox & who deactivated cashbox.

Using EF core code first approach.

Answer 1

With the following entity models -

public class User
{
    [Key]
    public int UserId { get; set; }
    public string UserName { get; set; }
}

public class CashBox
{
    [Key]
    public int CashBoxId { get; set; }
    public int ActivatedBy { get; set; }
    public int DeactivatedBy { get; set; }

    public User ActivatedUser { get; set; }
    public User DeactivatedUser { get; set; }
}

you can configure the relationship as -

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<CashBox>(e =>
    {
        e.HasOne(p => p.ActivatedUser)
        .WithMany()
        .HasForeignKey(p => p.ActivatedBy);

        e.HasOne(p => p.DeactivatedUser)
        .WithMany()
        .HasForeignKey(p => p.DeactivatedBy);
    });
}