How to create a self referencing tree #857

princedis created 8 years ago

I have to create a self referencing tree like category, subcategory entity which is similar to OrganizationUnit.

public class Category
{

    [Key]
    public int Id { get; set; }

    [StringLength(40)]
    public string Name { get; set; }

    public int? ParentId { get; set; }

    [JsonIgnore]
    public virtual ICollection<Category> Children { get; set; }

    [JsonIgnore]
    public virtual Category Parent { get; set; }
}

3 Answer(s)

0

hikalkan created 8 years ago
Support Team

Your entity seems fine except it must be derived from Entity class and should not include Id (since Entity defines it).

alaamh created 7 years ago

I have a question regarding application service implementation of GetCategories:

var categories = await _categoryRepository
                .GetAll()
                .Include(c => c.Children)
                .WhereIf(!input.Filter.IsNullOrEmpty(),
                    c => c.DisplayName.Contains(input.Filter)
                )
                .ToListAsync();

it's dump all the database, how to avoid that? I want to load only parent category with childrens of this parent

Thank you.

0

ismcagdas created 7 years ago
Support Team

Hi,

I think, it is really hard to write query of what you are asking with LinQ. Instead of this, get all list of categories and process them to create a tree in your app service.

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