[WinForms C#] Lesson 1 – Connection to Sql Database. (SQL Express MSSQL)

How to connect to SQL Database in WinForm C#.
Connecting to SQL Express Database Server
Store database credential in app config and call it in forms.
Connection Class Module

You may also download the full source code in github:
https://github.com/cadalzolc/winform-csharp-tutorials.git