CODEWITHSUNDEEP
asp.netlinqc#-4.0entity-framework-6.1
Learner
Learner

Reputation: 1315

LINQ query select entity and its collection query

I have an entity called Parent which has List of Children in it. now i want to select a parent and all its children order by display order.

    entities:- class parent{
                          Int id;
                          List<Child> children;
                           }

                class Child{ 
                            String name;
                            DateTime DOB;
                            Int DisplayOrder;
                           }

earlier i was getting a parent from Database using Linq to Entity as 

                context.Parents.Find(id);

This was doing everything fine. but now my requirement has changed now i need to select its children order by their display order. how can i do that. Any help is appreciated.

update parent class:-

              class parent{
                        public  Int id;
                        public virtual List<Child> children;
                           }

Upvotes: 0

Views: 113

Answers (3)

26071986
26071986

Reputation: 2330

That's in case you are sure that there can be only one parent with given ID.

var parent = context.Parents.Find(id);
parent.children = parent.children.OrderBy(cl => cl.DisplayOrder).ToList();

Upvotes: 0

Vladimirs
Vladimirs

Reputation: 8599

From info you provided I guess that you using your children somewhere to display them so you can use just parent.children.OrderBy(x => x.DisplayOrder).ToList() instead of simply parent.children that I suppose you had before.

Update 1.

Also I as far as I remember Find won't include your children. So worth to try something like:

var parent = context.Parents.Include(x => x.children).FirstOrDefault(x => x.id = id);
parent.children = parent.children.OrderBy(x => x.DisplayOrder).ToList();

Upvotes: 1

ETorre
ETorre

Reputation: 134

You have the Order By command on list, you can send to controller the "column" and order by this column

Upvotes: 0

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