Transform datetime to long or long to datetime in C#.
10 developer stories and 5 posts tagged with “C#”
A simple C# extension method which use Substring to get the last N characters in a string.
If you can, pass the connection string as a parameter to the class library. Second option is System.Configuration.ConfigurationManager
Configuring and using AutoMapper in a .NET CORE class library is briefed in this article.