When using the LINQ to SQL designer surface in Visual Studio, each time
you add an object (table, procedure, etc), you will end up adding
connection string information to your config file. This can be
confusing as the names used for the connection string may be different
then what you want to use and you may end up with multiple connection
strings, especially if you have multiple developers working on the same
To address this issue, you can:
Hopefully this will help you in clearly knowing which connection string will be used with your LINQ to SQL context classes.
- Create a partial class for your data context and create a parameter-less constructor as follows
public partial class LinqAppDataContext
In this example, I already have a LinqAppDataContext class, and I am
creating a partial class that calls the constructor on the base class
that takes a connection string. I then pull this connection string
from the config file.
- Step 1 is a one time setup. The remaining steps need to be followed each time you add a new object to the designer surface
- Add a new object to the designer surface (for example, drag a table from the Server Explorer)
- Click on an empty section of the designer surface (dbml file)
the properties window, go to Connection, then clear the information
from the Connection String property and then set the Application
Settings property to false. By doing this, the parameter-less
constructor from step 1 above will kick in and pull the connection
string from your config file.
- Verify that no extra connection strings have been added to your projects settings or config files