Entity Framework Code First Multiple Parent Maaping

Question

I'm trying to create these three models in EF 4.3:

 - Family
  - Guid FamilyId
  - ICollection< Person> Members
 - Company
  - Guid CompanyId
  - ICollection< Person> Employees
 - Person
  - Guid PersonId
  - String Name

A person can belong to multiple families and multiple companies, as well as doesn't belong to any.

After running the code, the mapping in the database seems a bit strange. Family-Members and Company-Employees were not mapped. Also, there are four columns in the Persons table: PersonId, Name, Family_FamilyId and Company_CompanyId.

I think my code is meant to be that a Person will always belong to 1 Family and 1 Company. How should I change the code?

Aron · Accepted Answer · 2013-10-12 10:17:28Z

You can't express all of this information in your classes as you figured out. To add extra information you have a few options.

You can add this to your EF context class

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{ 
    //All people must belong to a family.
    modelBuilder.Entity<Family>().HasMany(x => x.Members)
           .WithRequired();

    //Each person may belong to ZERO-Many companies.
    modelBuilder.Entity<Company>().HasMany(x => x.Employees)
           .WithMany();        
}

Or this to your EF context class

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{ 
    modelBuilder.Configurations.Add(new ComapnyMapper());
    modelBuilder.Configurations.Add(new FamilyMapper());

}

public class FamilyMapper : EntityTypeConfiguration<Family>
{
     public FamilyMapper()
     {
          HasMany(x => x.Members)
           .WithRequired();        
     }
}
public class CompanyMapper : EntityTypeConfiguration<Company>
{
     public CompanyMapper()
     {
          HasMany(x => x.Employees)
           .WithMany();        
     }
}

Jim · Accepted Answer · 2013-10-12 10:40:47Z

0

I ended up changing the model class to

Family
- Guid FamilyId
- ICollection< Person> Members
Company
- Guid CompanyId
- ICollection< Person> Employees
Person
- Guid PersonId
- String Name
- ICollection< Family> Families
- ICollection< Company> Companies

answered Oct 12, 2013 at 10:40

Jim

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