Best Practice For Deleting Member From Nested Collection

MarkPhillips · **Joined:** Mon Sep 28, 2009 11:29 am **Posts:** 4

Hi,

I'm trying to find the best practice for deleting a member from a collection that is nested within an aggregate. (DDD)

I have a Person class that contains an address collection. Inserts and Updates of addresses are successfully done through the Person class. I also want to delete an address through the Person class. If I just remove an address from the collection and call Session.Update(person) I get the following error:

Quote:

Cannot insert the value NULL into column 'PersonId', table 'PutTogether.dbo.PersonPhone'; column does not allow nulls. UPDATE fails.
The statement has been terminated.

The configuration for the Person on the Address is:

Code:

<many-to-one class="DomainModel.Person, DomainModel, Version=1.0.0.0, Culture=neutral, 
          PublicKeyToken=null" foreign-key="FK_PersonAddress_Person" name="Person">
           <column name="PersonId" not-null="true" /> 
 </many-to-one>

The configuration for the Addresses on the Person is:

Code:

<bag cascade="all" name="Addresses">
      <key>
            <column name="PersonId" /> 
       </key>
       <one-to-many class="DomainModel.PersonAddress, DomainModel, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" /> 
 </bag>

Thanks for your time,
Mark

wolli · **Posted:** Wed Oct 28, 2009 11:00 am

Try

<bag cascade="all-delete-orphan" inverse="true">

and don't forget to set adr.Person = null. Removing it from the collection isn't enough.

MarkPhillips · **Joined:** Mon Sep 28, 2009 11:29 am **Posts:** 4

Thanks for the response.

Here is the code and changes made. I also tested it without setting the Person to null. It's working fine this way as well.

Code:

public void DeleteAddress(int id, Guid personId) {
     var customer = GetById(personId);
     var address = GetExistingAddress(customer, id);
     customer.Addresses.Remove(address);
     Session.Update(customer);    
}

private PersonAddress GetExistingAddress(Customer customer, int id) {
     return customer.Addresses.Where(x => x.Id == id).FirstOrDefault();
}


<bag cascade="all-delete-orphan" inverse="true" name="Addresses">
     <key>
          <column name="PersonId" /> 
     </key>
     <one-to-many class="DomainModel.PersonAddress, DomainModel, Version=1.0.0.0, Culture=neutral,PublicKeyToken=null" /> 
  </bag>