Specify ON DELETE NO ACTION in ASP.NET MVC 4 C# Code First

Question

How do I specify ON DELETE NO ACTION Foreign Key Constraint in my model designs?

At present, I have:

public class Status {     [Required]     public int StatusId { get; set; }      [Required]     [DisplayName("Status")]     public string Name { get; set; } }  public class Restuarant {     public int RestaurantId { get; set; }     [Required]     public string Name { get; set; }     [Required]     [EmailAddress]     public string Email { get; set; }     [Required]     public string Telephone { get; set; }     [Required]     public int StatusId { get; set; }     public List<Menu> Menus { get; set; }      // NAVIGATION PROPERTIES     public virtual Status Status { get; set; } }  public class Menu {     public int MenuId { get; set; }      [Required]     public int RestaurantId { get; set; }      [Required]     public string Name { get; set; }      [Required]     public int StatusId { get; set; }      // NAVIGATION PROPERTIES     public virtual Status Status { get; set; }     public virtual Restaurant Restaurant { get; set; } } 

And my DbContext:

public class MenuEntities : DbContext {     public DbSet<Status> Statuses { get; set; }     public DbSet<Restaurant> Restaurants { get; set; }     public DbSet<Menu> Menus { get; set; } } 

As you can see:

• a Restaurant has many menus
• a Restaurant has one status
• a Menu belongs to 1 restaurant
• Both Restaurants and Menus have 1 status. (Live, Invisible, Draft)

Naturally, if a status is deleted, I certainly don't want to cascade as this will muck everything up.

UPDATE:

Mark Oreta mentions using the following in his example below:

modelBuilder.Entity<FirstEntity>()      .HasMany(f => f.SecondEntities)      .WithOptional()      .WillCascadeOnDelete(false);  

Where do I put this code? Within my MenuEntities / DbContext class? Can anybody provide an example of this being used?

UPDATE: Got this bit working now, however this has created a multiplicity constraint error when trying to seed the DB...

Multiplicity constraint violated. The role 'Menu_Status_Source' of the relationship 'LaCascadaWebApi.Models.Menu_Status' has multiplicity 1 or 0..1. 

My Database Initialiser:

http://pastebin.com/T2XWsAqk

Answer 1

You can either disable it for your entire context by removing the cascade delete convention in the OnModelCreating method:

  protected override void OnModelCreating( DbModelBuilder modelBuilder )   {      modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();   } 

or, you can do it per relationship using a fluent mapping (also in the OnModelCreating):

EDIT: you would put it in your menu entities

public class MenuEntities : DbContext {     public DbSet<Status> Statuses { get; set; }     public DbSet<Restaurant> Restaurants { get; set; }     public DbSet<Menu> Menus { get; set; }        protected override void OnModelCreating( DbModelBuilder modelBuilder )       {           modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();       modelBuilder.Entity<Menu>()         .HasRequired( f => f.Status )         .WithRequiredDependent()         .WillCascadeOnDelete( false );       modelBuilder.Entity<Restaurant>()         .HasRequired( f => f.Status )         .WithRequiredDependent()         .WillCascadeOnDelete( false );        }  }