im currently learning the entity framework and been miserably failing with this task for a couple of days... I would like to achieve the following Database Scheme:
TableA:
ClassA_ID
ClassB_ID(foreign key - one to one)
TableATableB:(one-to-many relationship)
ClassA_ID
ClassB_ID
TableB:
ClassA_ID(foreign key - one to one)
ClassB_ID
So I Actually want a specific one to one relationship from Class A to Class B and a one to many Relationship from ClassA to ClassB.
My C# Code Looks like this:
Class A:
public static int idcounter;
[Key]
public int id { get; set; }
public virtual List<ClassB> allClassB { get; set; }
public virtual ClassB currentClassB { get; set; }
public int? currentClassBID { get; set; }
public ClassA(){
idcounter++;
id = idcounter;
allClassB = new List<ClassB>();
currentClassB = new ClassB();
currentClassBID = currentClassB.id;
MyContext.add(this);
}
Class B:
public static int idcounter;
[Key]
public int id { get; set; }
public virtual ClassA owner { get; set; }
public int? ownerID { get; set; }
public ClassB(ClassA a){
idcounter++;
id = idcounter;
owner = a;
ownerID = a.id;
}
MyContext:
public static void add(ClassA a)
{
using (MyContext context = new MyContext ())
{
context.setB.Add(a.currentClassB);
context.setA.Add(a);
context.SaveChanges();
}
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<ClassA>().HasOptional(x => x.currentClassB ).WithMany().HasForeignKey(x => x.currentClassBID ).WillCascadeOnDelete(false);
modelBuilder.Entity<ClassB>().HasOptional(x => x.ClassA).WithMany(x => x.allClassB).HasForeignKey(x => x.ownerID).WillCascadeOnDelete(false) ;
}
Its pretty similar to this question Entity Framework Code First: How can I create a One-to-Many AND a One-to-One relationship between two tables? but I just get a Circular Exception when saving.
Unable to determine a valid ordering for dependent operations. Dependencies may
exist due to foreign key constraints, model requirements, or store-generated
values.
Its pretty weird that after
context.setA.Add(a);
it adds currentClassB into allClassB without me ever mention that... it Even suddenly does that when i dont
allClassB = new List<ClassB>();
What am I doing wrong?
