changing the connection string does not change database?

Question

I would like to switch between running on a database on the server (the real database) and a local copy that I keep for testing in localhost.

I tried to switch between db#1 (server) and db#2 (localhost) by changing the definition of the connection string in app.config (I also restarted VS to make sure nothing hides in memory). A strange thing happens: on the one hand if I query the db through datasource/preview data (in VS'10) indeed it brings the data from db#2. But when I run the application is still grabs the information from db#1, although as far as I know the connection string appears only in app.config, so I do not even understand where does it take the information from in order to connect to db#1.

While we're on the subject, what would be the more elegant way to switch between databases ? ideally from a pull-down menu I would chose the data source. But can I switch the connection string in run time ?

Answer 1

Visual studio maintains its own database connection info, presumably from its own app.config file. This is completely independent of your solutions app.config.

Switching databases as you suggest is relatively easy. Put 2 connection strings with different names in your app.config. Use a variable to hold the string you want and reference this wherever you are directly referencing the connection string now.