Creating the Data Model

There are two approaches that can be taken in creating the context and entity classes for your application. With the Code-First Approach approach, you can fine-tune your model by writing the classes manually. Alternatively, you can make use of Reverse Engineering (Scaffolding) to generate these classes automatically from your QuickBooks Online schema.

Perform LINQ Commands in Your Code

After Entity Framework Core is set up and the QuickBooks Online provider is registered, you can execute LINQ in your code.

using System.Linq;
using MySolutionName.Models;

System.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance); // Include this if you would like to use code pages not bundled in .NET Standard.
QuickBooksOnlineContext ents = new QuickBooksOnlineContext();
var CustomersQuery = from Customers in ents.Customers
                   orderby Customers.GivenName
                   select Customers;