Question

How to load an ADO.NET driver but when a connection is needed I want to specify the connection string manually which means through my code and without having it in the config file ?

If there’s no way to do this, what’s the best approach to achieve this, knowing that I’m writing an app that manages different databases (so different DBMS) that are inputted by the user himself ?

Answer 1

You can find plenty of examples here:

http://www.connectionstrings.com/

Example (using http://www.connectionstrings.com/postgre-sql):

var connection = new PostgreSqlConnection("Server=127.0.0.1;Port=5432;Database=myDataBase;User Id=myUsername;Password=myPassword");
connection.Open();

You can use db provider factory for interface based programming instead if driver specific.
http://msdn.microsoft.com/en-us/library/dd0w4a2z(VS.80).aspx

To create a factory:
http://msdn.microsoft.com/en-us/library/dd0w4a2z.aspx

Edit

I think I understand what you are looking for. To load the actual driver assembly at runtime. You can do that using the DbProviderFactory. You don’t need to add any driver specific references to your project when using it. However, the drivers must be installed on the computer =)