Question
I have two entities that should have many to many relationship.I provide test data.
public class A
{
public int AId {get;set;}
public virtual ICollection<B> Bs {get;set;}
}
public class B
{
public int BId {get;set;}
public virtual ICollection<A> As {get;set;}
}
public class AMap : EntityTypeConfiguration<A>
{
public AMap()
{
HasMany(e => e.Bs)
.WithMany(e => e.As)
.Map(x =>
{
x.ToTable("AandB");
x.MapLeftKey("AId");
x.MapRightKey("BId");
});
}
}
In this configuration I need set cascade delete.For example when I delete any row in table A,I need that all related rows in table AandB will be deleted.But I can't find syntax for many to many.Can anybody help me?
Accepted Answer
After searching I've found solution.To delete entity from many-to-many relationship you need load the related navigation property In my case:
var AtoDelete= context.As.Include(a => a.Bs) .First(); //include is mandatory
context.As.Remove(AtoDelete);
context.SaveChanges();//deletes will be issued to AandB table also.
Popular Answer
As I know there is no way to directly turn on cascade deletes on Many to Many associations in fluent API. you have to delete related entities explicitly.
var a = context.A.Include(a => a.Bs).First();
foreach(var b in a.Bs)
{
context.Entry(b).State = EntityState.Deleted;
}
context.Entry(a).State = EntityState.Deleted;
context.SaveChanges();
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