CODEWITHSUNDEEP
c#entity-framework
garyson ford
garyson ford

Reputation: 71

Fetching childrens of an entity in Entity Framework

I have an entity called

Public  Class Equipment
{
    int Id;
    string EquipmentName;
    int? ParentEquipmentId;
}

So have this entity where an equipment can have a parent and child relationship. I want to fetch the parent equipment and also all the children of the equipment associated with it.

Can i have ICollection on the entity to fetch me the childrens??

Upvotes: 0

Views: 214

Answers (3)

garyson ford
garyson ford

Reputation: 71

Public  Class Equipment
{
    int Id;
    string EquipmentName;
    int? ParentEquipmentId;
    virtual Equipment Parent;
    Virtual ICollection<Equipment> Childrens
}

Model binder use fluent api

   this.HasOptional(e => e.Parent)
                .WithMany(e => e.Children)
                .HasForeignKey(m => m.ParentEquipmentId);

This will pull the records associated with the

Upvotes: 2

xwrs
xwrs

Reputation: 1297

Seems that you need something like this (not the precise syntax)

Parent and Children properties:

public Equipment Parent 
{
    get 
    {
        return dataContext.DbSet<Equipment>().SingleOrDefault(e=>e.Id == this.ParentEquipmentId);
    }
}

public IEnumerable<Equipment> Children 
{
    get 
    {
        return dataContext.DbSet<Equipment>().Where(e=>e.ParentEquipmentId == this.Id);
    }
}

And use your Parent property to get all child Equipment of this particular parent:

this.Parent.Children

Upvotes: 0

Wojciech
Wojciech

Reputation: 234

Yes you need to include collection of children in your object:

public virtual ICollection<Equipment> Children { get; set; }

and remember to add .Include(q => q.Children) to your linq query to load children.

Upvotes: 0

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