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:
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:
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 );
}
}