Simple.Data insert complex object

Question

It's my first day with Simple.Data. I am migrating my project from pure ADO .NET.

I have an Order table with columns:

Id
CreationDate
CustomerId  -> FK to Customer table

And an Order class in my project:

int Id
DateTime CreationDate    
Customer Customer

To insert new Order to database I am doing:

var newOrder=...
_db.Orders.Insert(new {
                       CreationDate=newOrder.CreationDate,
                       CustomerId = newOrder.Customer.Id
                      }
                 );

Is it possible to do it simplier? Simplier for me means without creating new anonymous object and copying each property value. I know that Simple.Data provide Implicit Casting with Insert but when I am trying this:

var newOrder=...
_db.Orders.Insert(newOrder);

I am getting an Exception "CustomerId cannot be NULL" from my SqlServer.

score 1 · Accepted Answer · answered Oct 01 '13 at 06:12

I don't think it's possible at the moment, but Mark is looking into "allowing object graphs to be saved with a single call, if that’s actually possible" for v2 (see his blog post: http://blog.markrendle.net/2013/09/18/simple-data-2-0/, especially the "Better WithStuff" paragraph).

However you could avoid copying each property value by converting your "newOrder" object to dynamic and simply "adding" the "CustomerId" value to it, like this:

var d = newOrder.ToDynamic();
d.CustomerId = newOrder.Customer.Id;
_db.Orders.Insert(d);

where "ToDynamic()" is a simple extension method:

public static dynamic ToDynamic(this object @this)
{
    IDictionary<string, object> expando = new ExpandoObject();

    foreach (PropertyDescriptor property in TypeDescriptor.GetProperties(@this.GetType()))
    {
        expando.Add(property.Name, property.GetValue(@this));
    }

    return expando as ExpandoObject;
}

Simple.Data will ignore the original "Customer" property during insert, as the underlying table does not have column for this.

thank you for that. I've just added CustomerId property to my Order class statically, but your solution with ToDynamic is just cleaner. Looking forward Simple.Data v2. — GrzegorzM, Oct 14 '13 at 21:01

score 0 · Answer 2 · answered Sep 23 '13 at 14:58

0

The customer ID cannot be null. You need logic that doesn't insert the data into the db when CustomerId is null.

if (newOrder.Customer != null && newOrder.Customer.Id != null)
{
    _db.Orders.Insert(new 
    {
         CreationDate=newOrder.CreationDate,
         CustomerId = newOrder.Customer.Id
    });
}

answered Sep 23 '13 at 14:58

Jon La Marr

1,358
11
14

1

You misunderstood my question. Customer && Customer.Id is not null for sure. I was asking, does Simple.Data can match [Order].[CustomerId] column with Customer.Id property while inserting. For example by a foreign key between [Order].[CustomerId] and [Customer].[Id] columns (just as doing it while SELECTing data from database) – GrzegorzM Sep 23 '13 at 15:09

Simple.Data insert complex object

2 Answers2