List of Child model not updating when parent is updating

Question

I have these models:

public class GroupSetCollection {
    int Id { get; set; }
    string Name { get; set; }
    List<GroupSet> GroupSets { get; set; }
}

public class GroupSet {
    int Id { get; set; }
    string Name { get; set; }
    List<Group> Groups{ get; set; } 
}

Whenever I update the GroupSetCollection all the properties are updated except for the GroupSets. When I manually call the update on the GroupSet it gives me the following error.

Attaching an entity of type 'GroupSet' failed because another entity of the >same type already has the same primary key value for child.`

Below is the method I'm using to update the entities. It fails at the GroupSet update and works fine on the GroupSetCollection update.

public void UpdateGroupSetCollection(GroupSetVM groupSetCollection)
        {
            _GroupSetCollectionService.Update(VMToEntity(groupSetCollection));
            _GroupSet.Update(groupSetCollection.GroupSets);

        }

If `List GroupSets` are related with the `GroupSetCollection`, it isn't necessary update the entities individualy. So, when `GroupSetCollection` is updated, its entities related are also updated. Maybe adding `public virtual List GroupSets {get; set;}` will fix the problem. — JPocoata, Sep 04 '18 at 16:26
Possible duplicate: https://stackoverflow.com/questions/27176014/how-to-add-update-child-entities-when-updating-a-parent-entity-in-ef — Gauravsa, Sep 05 '18 at 01:12
@JesusPocoata That's it! They weren't set to virtual that was my issue. Thanks for your help. — Jack Tyler, Sep 05 '18 at 09:56

score 1 · Accepted Answer · answered Sep 05 '18 at 13:19

There are many ways to load related entities, one of them is add the word virtual to the related entity.

So, you final class will be:

public class GroupSetCollection {
    public int Id { get; set; }
    public string Name { get; set; }
    public virtual List<GroupSet> GroupSets { get; set; }
}

You could also read about Loading Related Entities from the official documentation.

score 0 · Answer 2 · answered Sep 05 '18 at 09:57

0

Thanks to @JesusPocoata for helping my figure out the issue.

I hadn't set the List<GroupSet> to virtual once that was done it worked perfectly.

answered Sep 05 '18 at 09:57

Jack Tyler

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List of Child model not updating when parent is updating

2 Answers2