Duplicate navigation properties when using Entity Framework 6 and fluent api
c# entity-framework entity-framework-6 fluent foreign-keys
Question
I got two models with a relations.
public class Customer
{
public Customer()
{
CustomerSites = new List<CustomerSite>();
}
public IList<CustomerSite> CustomerSites { get; set; }
}
public class CustomerSite
{
public Guid CustomerId { get; set; }
public Customer Customer { get; set; }
}
The relations is built up by fluent api: (I have tried also with only one of the statement below)
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<CustomerSite>()
.HasRequired(x => x.Customer)
.WithMany(x => x.CustomerSites)
.HasForeignKey(x => x.CustomerId);
modelBuilder.Entity<Customer>()
.HasMany(x => x.CustomerSites)
.WithRequired(x => x.Customer)
.HasForeignKey(x => x.CustomerId);
}
My question is why this code generates double foreign keys to the database like example below.
"dbo.CustomerSites",
c => new
{
CustomerId = c.Guid(nullable: false),
Customer_Id = c.Guid(),
})
.ForeignKey("dbo.Customers", t => t.CustomerId, cascadeDelete: true)
.ForeignKey("dbo.Customers", t => t.Customer_Id)
It should only be one CustomerId and not Customer_Id. As you see this is also nullable. If I remove this column in the db context is throwing exception on update. I think this is quite weird....
Popular Answer
The reason was that during re-factoring some old properties were left in the entity that influenced during auto-mapping on additional FKs in the DB.
Example: if we have
public class CustomerSite
{
public Guid CustomerId { get; set; }
public Customer Customer { get; set; }
............
public Customer Customer1 { get; set; }
}
and have only one fluent mapping statement like
modelBuilder.Entity<CustomerSite>().HasRequired(x => x.Customer)
.WithMany(x => x.CustomerSites).HasForeignKey(x => x.CustomerId);
in the database we will have additionak FK like Customer1_Id which will be nullable.
Be attentive. May be it helps someone!!!