When writing a console application using C# / .NET and you want to connect to a database, the connection string is typically stored in the app.config file. Below is an example of a web.config which is the same an app.config file used in C#.Net. It is essentially an XML file that stores required data to make your application work. It keeps these bits of data in one place, making it easy to manage when things change. There will be no need to hunt down connection strings or other configuration data with in your application code.

To extend further on this top tip I have written a tutorial on how to use CSharp with MySQL.

 <?xml version="1.0" encoding="utf-8" ?>
    <configuration>
       <ConnectionString>
         <add key="MySQL.DB" value="server=localhost;database=mysqldbname;user=username;password=12345678;" />
       </ConnectionString>

       <system.web>
        <compilation defaultLanguage="c#" debug="true" />
      </system.web>

    </configuration>

To access the connection string the first step would be to make sure that a reference is added to System.Configuration. Then make sure you include it in the class using System.Configuration and the code below is used to access the connection string.To access the connection string the first step would be to make sure that a reference is added to System.Configuration. Then make sure you include it in the class using System.Configuration and the code below is used to access the connection string.

using System.Configuration;

string MysqlConnectionString = ConfigurationManager.ConnectionStrings["dbconnectionstring"].ConnectionString;

This method can also be used to access the app.config file for any web applications.