How to map two properties in one code first object to the same parent type - entity-framework

Question

I've been at this for hours and have tried many suggestions I found searching but no luck. I'm using code first EF 5.
The situation is that I have a class Employee. Then I have another class that has two properties on it, both are of type Employee. I want these both to be foreign key constraints but the requirements allow many of the same requests to and from the same users so I can't just use them as keys. I don't really care about Employee having the two collections for navigation but in my working through the problem that seemed a requirement. If it simplifies the problem I can remove those.
I get this message.
System.Data.Entity.Edm.EdmAssociationEnd: : Multiplicity is not valid in Role 'Employee_RequestsForEmployee_Target' in relationship 'Employee_RequestsForEmployee'. Because the Dependent Role properties are not the key properties, the upper bound of the multiplicity of the Dependent Role must be '*'.
I've tried this using the Fluent API in the OnModelCreation method of the context;
modelBuilder.Entity()
.HasRequired(u => u.ForEmployee)
.WithMany()
.HasForeignKey(u => u.ForEmployeeId);
modelBuilder.Entity<RevenueTransferRequest>()
.HasRequired(u => u.FromEmployee)
.WithMany()
.HasForeignKey(u => u.FromEmployeeId);
The classes in conflict are (I've removed some properties for clarity);
public class Employee : IEmployee
{
[Key]
public string Id { get; set; }
[InverseProperty("ForEmployee")]
public ICollection<RevenueTransferRequest> RequestsForEmployee { get; set; }
[InverseProperty("FromEmployee")]
public ICollection<RevenueTransferRequest> RequestsFromEmployee { get; set; }
}
public class RevenueTransferRequest : IRevenueTransferRequest
{
[Key]
public Guid Id { get; set; }
[Required]
[ForeignKey("ForEmployee")]
public String ForEmployeeId { get; set; }
[InverseProperty("RequestsForEmployee")]
public Employee ForEmployee { get; set; }
[Required]
[ForeignKey("FromEmployee")]
public String FromEmployeeId { get; set; }
[InverseProperty("RequestsFromEmployee")]
public Employee FromEmployee { get; set; }
}
Any help would be much appreciated. Thanks in advance.

Answer 1

I never did figure out how to do it using data annotations but using the Fluent API I was able to do it. What I was missing was that I had to specify in the HasMany() method what the relationship on the other side was which I assumed was understood through the data annotations and conventions.
This is called in the DbContext OnModelCreating override (The WillCascadeOnDelete(false) is related to another issue).
modelBuilder.Entity<RevenueTransferRequest>()
.HasRequired(e => e.FromEmployee)
.WithMany(x=>x.RequestsFromEmployee)
.WillCascadeOnDelete(false);
modelBuilder.Entity<RevenueTransferRequest>()
.HasRequired(e => e.ForEmployee)
.WithMany(x => x.RequestsForEmployee)
.WillCascadeOnDelete(false);
With the classes:
[Key]
public String Id { get; set; }
public String BusinessUnitLeaderId { get; set; }
public Employee BusinessUnitLeader { get; set; }
[Required]
[MaxLength(150)]
public String DisplayName { get; set; }
public ICollection<Project> BusinessUnitLeaderProjects { get; set; }
public ICollection<RevenueTransferRequest> RequestsForEmployee { get; set; }
public ICollection<RevenueTransferRequest> RequestsFromEmployee { get; set; }
public class RevenueTransferRequest
{
[Key]
public Guid Id { get; set; }
[Required]
public String ForEmployeeId { get; set; }
public Employee ForEmployee { get; set; }
[Required]
public String FromEmployeeId { get; set; }
public Employee FromEmployee { get; set; }
[Required]
public String ProjectId { get; set; }
public Project Project { get; set; }
[Required]
public Double? TransferAmount { get; set; }
public int WorkflowState { get; set; }
}