Managing A Debug and Release Connection String

Question

What is a good approach to managing a debug and release connection string in a .NET / SQLServer application?

I have two SQL Servers, a production and a build/debug and I

Answer 1

I use a combination of Sameh's and Obalix's method in .net 3.5.

    public static class DataConnection
{
#if LOCALDEV
    public const string Env = "Debug";
#endif
#if STAGING
    public const string Env="Staging";
#endif
#if RELEASE
    public const string Env="Release";
#endif
    private static ConnectionStringSettingsCollection _connections;
    static DataConnection()
    {
        _connections = ConfigurationManager.ConnectionStrings;

    }

    public static string BoloConnectionString
    {
        get
        {
            return _connections["DB1."+Env].ConnectionString;
        }
    }
    public static string AOAConnectionString
    {
        get
        {
            return _connections["DB2."+Env].ConnectionString;
        }
    }
    public static string DocVueConnectionString
    {
        get
        {
            return _connections["DB3."+Env].ConnectionString;
        }
    }
}

Then in my project properties, I define the right conditional compilation symbols. This way I don't have to keep my connection strings hard coded like Sameh's, but the code only looks for the string based on how it was built. This lets me have (if I need to) one config file for all the builds, but in reality I don't deploy the config files in my build process. Although the conditional app.Relase.config stuff for .net 4 looks like the right way to go in the future.