Fluent nhibernate One-to-Many when Inverse is used Child table's Foreign key is null

问题

I have a parent and child table and entites are created and mapped using one to many relation ship. On one to many side when i use Inverse() then the child table's foreign key value is inserted as null.

public class TableA
{
   public virtual long ID { get; set; }
   public virtual string Name { get; set; }
   public virtual IList<TableB> TableB { get; set; }
}

public class TableB
{
   public virtual long ID { get; set; }
   public virtual string Name { get; set; }
   public virtual TableA TableA { get; set; }
}

public class TableAMap : ClassMap<TableA>
{
   public TableAMap()
   {
      Id(x=>x.ID);
      Map(x=>x.Name).Column("Name");
      HasMany(x=>x.TableB)
          .KeyColumn("TableA_ID")
          .Inverse()
          .Cascase.All()
          .Not.LazyLoad();
   }
}

public class TableBMap : ClassMap<TableB>
{
   public TableBMap()
   {
      Id(x=>x.ID);
      Map(x=>x.Name).Column("Name");
      References(x=>x.TableA).Column("TableA_ID").Not.LazyLoad();
   }
}

Note When the Inverse() is removed from many to one the new records are inserted without any issues and the foreign key is inserted without any issues but when i update a record the foreign key of the existing records are replaced as null.

Please help me i looked in to similar questions but it doesn't help me.

Fluent NHibernate one-to-many relationship setting foreign key to null

回答1:

Refer to this link which has the solution for this issue.

Refer this Solution link

The map class should be:

public class TableAMap : ClassMap<TableA>
{
   public TableAMap()
   {
      Id(x=>x.ID);
      Map(x=>x.Name).Column("Name");
      HasMany<TableB>(x=>x.TableB)
          .KeyColumn("TableA_ID")
          .Cascade.All().Inverse();
   }
}

public class TableBMap : ClassMap<TableB>
{
   public TableBMap()
   {
      Id(x=>x.ID);
      Map(x=>x.Name).Column("Name");
      References<TableA>(x=>x.TableA).Column("TableA_ID").Not.Nullable();
   }
}

回答2:

it's hard to tell exactly without seeing the code which inserts. However my crystal ball tells me you probably forgot the last line

Parent parent = new Parent();
Child child = new Child();
parent.Children.Add(child);
child.Parent = parent;     <-- this is important because this will maintain the foreign key

来源：https://stackoverflow.com/questions/13576222/fluent-nhibernate-one-to-many-when-inverse-is-used-child-tables-foreign-key-is