EF Fluent API C＃级联删除问题

Question

I am having problems configuring a model to not cascade delete.

The modeL.

public class Hit
{
    public int Id { get; set; }

    // Foreign Key
    public int AccountId { get; set; }

    // Foreign Key
    public int LeadId { get; set; }

    //navigation properties
    [ForeignKey("LeadId")]
    public Lead lead { get; set; }

    //navigation properties
    [ForeignKey("AccountId")]
    public Account account { get; set; }

}

Fluent API:

 modelBuilder.Entity<Hit>()
          .HasRequired(t => t.lead)
          .WithMany()
          .HasForeignKey(t => t.LeadId)
          .WillCascadeOnDelete(false);

When I try to migrate it, i get this in create table on Hit:

.ForeignKey("dbo.Accounts", t => t.AccountId, cascadeDelete: true)
.ForeignKey("dbo.Leads", t => t.Lead_Id)
.ForeignKey("dbo.Leads", t => t.LeadId, cascadeDelete: true)

What I want to achieve for both leads and accounts is this in the migration script:

.ForeignKey("dbo.Leads", t => t.LeadId)

How should I go about doing this? Its prbably easy, but I am new to all this:(

EDIT 1:

I added this to the fluent API:

 modelBuilder.Entity<Lead>().HasMany(i => i.Hits).WithOptional().HasForeignKey(s=> s.LeadId).WillCascadeOnDelete(false);

Which remove cascadelete from: .ForeignKey("dbo.Leads", t => t.LeadId)

However, I also want to remove it from:

 .ForeignKey("dbo.Accounts", t => t.AccountId, cascadeDelete: true)

The easy solution would be to remove it from the migration script. But I would like how to do this with FLuent API or other methods.

Any ideas?

Answer 1

Like I already said in the comments above, if you use Fluent API for mapping your FKs remove the [ForeignKey] attributes from your navigation properties.

You can then do non-cascading mappings like this:

modelBuilder.Entity<Hit>().HasOptional(m => m.account).WithMany().HasForeignKey(m
=> m.AccountId).WillCascadeOnDelete(false);

Finally you have to check if your FK columns should be optional or required, for optional mappings change your FK properties AccountId and LeadId to data type int? , otherwise you have to change the HasOptional() part of your FK mappings to HasRequired() .

Answer 2

Define your model like so:

public class Hit
{
    public int Id { get; set; }

    public virtual Lead Lead { get; set; }

    public virtual Account Account { get; set; }
}

The virtual keyword will let Entity Framework know you are defining a foreign key and will match on Id automatically.

Remove the HasRequired(t => t.lead).WithMany() part from Fluent API. If a property is required it cannot exist without it and will cascade on delete.