Question

I’m working on a WinForm application. I’ve implemented data-access logic into a “library project” that I set as reference in my WinForm project. I’m using LINQ to SQL to connect to my project database, mapping the tables I use into a dbml file. Now I have to publish my project and change the connection string to point to the production DB.

Is it possible to change the connection string without re-compile the project?
It’ll be very useful at debug-time and for maintenance…

I’ve tried to change it in app.config and also in the Settings file, but it seems to still point to the development DB.

Where am I doing wrong?

Answer 1

The solution suggested in this article is very good: http://goneale.com/2009/03/26/untie-linq-to-sql-connection-string-from-application-settings/

But I decided to solve my issue in a different way.

Without modifying anyting in the dbml file I added in my DAO class a constructor that takes a parameter:

public MyDataAccessClass(string connectionString)
{
     _connString = connectionString;
}

then instead of using DataClasses() constructor to instantiate the LINQ-TO-SQL class, I replaced it with DataClasses(_connString).

Now I can use the data access library where I need. The connection string will be set in app.config of the referencig application (or anywhere else).