The hierarchyid data type is a variable-length system data type. You can use the hierarchyid to represent the position in a hierarchy.
EntityFrameworkCore.SqlServer.HierarchyId is a NuGet library for Microsoft.EntityFrameworkCore that adds hierarchyid support to the SQL Server EF Core provider.
You can easily install it from the Package Manager Console window by running the following command.
PM> Install-Package EntityFrameworkCore.SqlServer.HierarchyId
To start using the EntityFrameworkCore.SqlServer.HierarchyId in your application, you will need to install the EntityFrameworkCore.SqlServer.HierarchyId NuGet package.
Let's open the Visual Studio and create a new project.
Select the Create a new project option.
Choose C# as language, Windows as a platform, and Console as the project type. In the template pane, select Console Application and click the Next button.
Enter the project name, you can change the location and solution name, but we will leave it and click on the Next button.
On the Additional Information dialog, select the target framework and then click on the Create button.
You can see a new console application project is created. Now to install an EntityFrameworkCore.SqlServer.HierarchyId, right-click on the project in Solution Explorer, and select Manage NuGet Packages...
Select the Browse tab and search for EntityFrameworkCore.SqlServer.HierarchyId and install the latest version by pressing the Install button.
Once EntityFrameworkCore.SqlServer.HierarchyId has been successfully installed. Let's add the database provider that you want to target. We will use SQL Server, and the provider package is Microsoft.EntityFrameworkCore.SqlServer. We can easily install that NuGet package by executing the following command in Package Manager Console.
PM> Install-Package Microsoft.EntityFrameworkCore.SqlServer
You are now ready to start your application.