問題タブ [self-referencing-table]

したがって、子条件を持つ Group オブジェクトがあります。Condition オブジェクトには、条件の自己参照型の子関連付けもあります。

グループ has_many :条件

条件の所属先:グループには_多くの条件:条件

レベルごとに明示的にリストする必要のない強力なパラメーターで複数のレベルを指定する良い方法はありますか (複数のレベルなどがある場合があります)。

I have set up a self referential entity using EF Core which looks like this:

Entity

Binding

I am retrieving these entities via an API and the current result looks something like this:

The problem I have with this is that the third item in the array is just the reverse of the second. Is there a way to avoid this so that I only have the parent -> child relationship rather than both parent -> child as well as child -> parent. The example above is a heavily cut-down version of what my API is actually returning so I want to reduce the unnecessary bloat as much as possible because there'll be a lot of relationships going on.

Ideally what I want is to just get rid of the ParentType property but still have the ChildTypes collection but I'm not sure how to define that in the model builder.

EDIT:

I have removed the fluent relationship as it's not needed. I've also tried the following:

(this.Items is the DbSet by the way)

However this requires changing ChildTypes to an IQueryable and when I do that I get the following exception:

The type of navigation property 'ChildTypes' on the entity type 'DetailType' is 'EntityQueryable' which does not implement ICollection. Collection navigation properties must implement ICollection<> of the target type.

私はこのように見えるテーブルをバインドしようとしています

ご覧のように、

• 自己参照エンティティのように見えます
• の FK なしparent_id
• parent_idnull 可能ではなく、デフォルトは0

どうすればバインドできますか?

次のマッピングは問題ありませんか?

つまり、どのように にマップでき0ますnullか?