Multiple Foreign Key for Same table in Entity Framework Code First

Question

I have two entities in my application and I populated the database with Entity Framework Code First. There are two Employee id in the Task entity; one of them forRequirerEmploye, others for RequestedEmployee. When make update-database in package manager console I get error like this:

Introducing FOREIGN KEY constraint 'FK_dbo.Tasks_dbo.Employees_DemandingEmployeeID' on table 'Tasks' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.

My Task Class:

    public int ID { get; set; }
    public int DemandingEmployeeID { get; set; }
    public int RequestedEmployeeID { get; set; }



    [ForeignKey("DemandingEmployeeID")]
    [InverseProperty("DemandingTasks")]
    public virtual Employee DemandingEmployee { get; set; }

    [ForeignKey("RequestedEmployeeID")]
    [InverseProperty("RequestedTasks")]

    public virtual Employee RequestedEmployee { get; set; }

My Employee Class:

    public int ID { get; set; }

    public virtual ICollection<Task> DemandingTasks { get; set; }    
    public virtual ICollection<Task> RequestedTasks { get; set; }

My Context:

   modelBuilder.Entity<Task>().HasRequired(m => m.DemandingEmployee).WithMany(m => m.DemandingTasks).HasForeignKey(m => m.DemandingEmployeeID);
        modelBuilder.Entity<Task>().HasRequired(m => m.UpdatedEmployee).WithMany(m => m.UpdatedTasks).HasForeignKey(m => m.UpdatedEmployeeID);

Fabio Luz Fabio Luz · Accepted Answer · 2015-12-18T13:20:55

The problem is that you have multiple paths of cascade deletes, that could end trying to delete the same row in the database. To understand more about this error, take a look at https://support.microsoft.com/en-us/kb/321843. Follow the steps above to solve the problem.

Change your class:

public int ID { get; set; }
public int DemandingEmployeeID { get; set; }
public int RequestedEmployeeID { get; set; }

public virtual Employee DemandingEmployee { get; set; }
public virtual Employee RequestedEmployee { get; set; }

Change your context:

modelBuilder.Entity<Task>()
     .HasRequired(m => m.DemandingEmployee)
     .WithMany(m => m.DemandingTasks)
     .HasForeignKey(m => m.DemandingEmployeeID)
     .WillCascadeOnDelete(false);

modelBuilder.Entity<Task>()
     .HasRequired(m => m.RequestedEmployee)
     .WithMany(m => m.RequestedTasks)
     .HasForeignKey(m => m.RequestedEmployeeId)
     .WillCascadeOnDelete(false);

modelBuilder.Entity<Task>()
    .HasRequired(m => m.UpdatedEmployee)
    .WithMany(m => m.UpdatedTasks)
    .HasForeignKey(m => m.UpdatedEmployeeID)
    .WillCascadeOnDelete(false);

Multiple Foreign Key for Same table in Entity Framework Code First

1 Answers