XAML C# How to work with the database?

Question

C++ / C#

XAML C# How to work with the database?
Tried to insert my previously written class...
But it doesn't work
complains about System.Data.Sql;
System.Data.SqlClient;
there is no type of them
What to do?
Start learning LINQ?

Answer 1

using System.Data.Sql;
using System.Data.SqlClient;

Answer 2

What platform? Desktop, Windows Store, Windows Phone?
For all three platforms, you can use, for example, the SQLite.Net PCL library https://www.nuget.org/packages/SQLite.Net-PCL/

Answer 3

mb in the project to add links to the necessary libraries?