How to get relational data from azure mobile app

Question

Hello I am trying to get relational data using entity frame work from an Azure mobile App.

The info in this tutorial talks a lot about formatting but not about relationships. This one Has related data using entity framework but nothing about azure mobile apps. In this case they use ASP.net Core. How can I put the information from the two together?

I attempted to set up relationships in a similar manner however it does not acknowledge the relationships at all. Does anybody know what to do?

Update Following advice I managed to get the foreign keys to show in the migration so.

The entity definitions are as follows

public class Member : EntityData
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Address { get; set; }
    public virtual ICollection<Subscription> Subscriptions { get; set; }


}

public class Subscription : EntityData
{
    public string MemberId { get; set; }
    public string ShopItemId { get; set; }
    public virtual Member Member { get; set; }
    public virtual ShopItem ShopItem { get; set; }
    public int Quantity { get; set; }
}
public class ShopItem : EntityData
{
    public decimal Price { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }
    public string Note { get; set; }
}

I suspect that I do not need the virtual properties but I'll leave them in since they are there on the client side.

The migration shows the correct relationship in terms of foreign keys

CreateTable(
            "dbo.Subscriptions",
            c => new
                {
                    Id = c.String(nullable: false, maxLength: 128,
                        annotations: new Dictionary<string, AnnotationValues>
                        {
                            { 
                                "ServiceTableColumn",
                                new AnnotationValues(oldValue: null, newValue: "Id")
                            },
                        }),
                    MemberId = c.String(maxLength: 128),
                    ShopItemId = c.String(maxLength: 128),
                    Quantity = c.Int(nullable: false),
                    Version = c.Binary(nullable: false, fixedLength: true, timestamp: true, storeType: "rowversion",
                        annotations: new Dictionary<string, AnnotationValues>
                        {
                            { 
                                "ServiceTableColumn",
                                new AnnotationValues(oldValue: null, newValue: "Version")
                            },
                        }),
                    CreatedAt = c.DateTimeOffset(nullable: false, precision: 7,
                        annotations: new Dictionary<string, AnnotationValues>
                        {
                            { 
                                "ServiceTableColumn",
                                new AnnotationValues(oldValue: null, newValue: "CreatedAt")
                            },
                        }),
                    UpdatedAt = c.DateTimeOffset(precision: 7,
                        annotations: new Dictionary<string, AnnotationValues>
                        {
                            { 
                                "ServiceTableColumn",
                                new AnnotationValues(oldValue: null, newValue: "UpdatedAt")
                            },
                        }),
                    Deleted = c.Boolean(nullable: false,
                        annotations: new Dictionary<string, AnnotationValues>
                        {
                            { 
                                "ServiceTableColumn",
                                new AnnotationValues(oldValue: null, newValue: "Deleted")
                            },
                        }),
                })
            .PrimaryKey(t => t.Id)
            .ForeignKey("dbo.Members", t => t.MemberId)
            .ForeignKey("dbo.ShopItems", t => t.ShopItemId)
            .Index(t => t.MemberId)
            .Index(t => t.ShopItemId)
            .Index(t => t.CreatedAt, clustered: true);

However when making a request to the table api the result is still

{"deleted":false,"updatedAt":"2016-12-07T21:55:19.174Z","createdAt":"2016-12-07T21:55:19.128Z","version":"AAAAAAAAB/s=","id":"1","quantity":1,"shopItemId":"1","memberId":"1"}

which does not include the related entity.

Answer 1

I'm new at this too, but I just discovered that it seems to detect relationships automatically if you name your fields appropriately.

Item Table
_______
Id
PersonId

Person Table
____________
Id
FirstName
LastName

In this case here, PersonId in the Item table would match Id in the Person Table.

I am very new to this, so I could be way off, but this is my understanding of it so far.

Just set it up in your model and look at the migration file and see if it picked it up. You'll be able to tell by looking at the code in the migration file.

Update:

Here it is is code. I have not dealt with lazy loading, so I'm not sure how to do that.

class Item
{
  string Id { get; set; }
  string PersonId { get; set; } // This matches Person class Id property
}

class Person
{
  string Id { get; set; }
  string FirstName { get; set; }
  string LastName { get; set; }
}

Another Update:

I just figured out how foreign keys work.

public class GameObject : EntityData
{
    public string PlayerId { get; set; }
    public virtual Player player { get; set; }
}

 public class Player : EntityData
 {
    public string FirstName { get; set; }
    public string LastName { get; set; }
 }

The virtual property tells it that it's a foreign key. Without it, you won't see

.ForeignKey("dbo.Players", t => t.PlayerId)

in your migration when it's created.

In addition, to retrieve the related data, you have to follow the steps listed here: (blogs.msdn.microsoft.com/azuremobile/2014/05/27/