Can we declare variables in the 'app.config' file?

Question

I have a form which needs to get connected to SQL Server, and I have a drop down for selecting the list of databases and perform operations like primary key checking, etc.

Answer 1

I think he wants a "semi constant":

Web.Config

CS file

String Servername = "Test";
String ConnectionString = String.Format(ConfigurationManager.ConnectionStrings["YourName"].ConnectionString, ServerName);