Implementing the query object pattern

In this recipe, we will be implementing the Query Object pattern on top of Entity Framework Core to leverage maximum reuse without surfacing queryable collections to the consuming developers. The Query Object pattern allows encapsulating and making parameterizable queries without actually exposing what it does.

Getting ready

We will be using the NuGet Package Manager to install the Entity Framework Core 1 package, Microsoft.EntityFrameworkCore. We will also be using a SQL Server database for storing the data, so we will also need Microsoft.EntityFrameworkCore.SqlServer.

Finally, xunit is the package we will be using for the unit tests and dotnet-text-xunit adds tooling support for Visual Studio. Note that the UnitTests project is a .NET Core App 1.0 (netcoreapp1.0), that Microsoft.EntityFrameworkCore.Design is configured as a build dependency, and Microsoft.EntityFrameworkCore.Tools is set as a tool.

Open Using EF Core Solution from the included source code...