Best way to set strongly typed dataset connection string at runtime?

Question

My Windows Forms application uses a strongly typed dataset created using the designer in Visual Studio. At runtime I would like to be able to select either the live or test data

Answer 1

Connection property in TableAdapters is defined as internal.

internal global::System.Data.SqlClient.SqlConnection Connection

So in case your TypedDataset is not in the same assembly as your main windows forms app, you will not be able to access Connection property. This problem might popup later when you refactor your dataset code and move it into a seperate project which will produce its own independant assembly.

To solve this problem, you can do as mentioned below.

create partial class for your TableAdapter and add another constructor beside the default public parameterless constructor. Assuming TableAdapter type as MyTableAdapter

public partial class MyTableAdapter
{
    public MyTableAdapter(SqlConnection connection)
    {
        thisSetConnection(connection);
        this.ClearBeforeFill = true;
    }

    public void SetConnection(SqlConnection connection)
    {
        this._connection = connection;
    }
}

You will need to do this for as many as TableAdapters you have in your project. TableAdapter does not have any common base class but thanks that they are declared as partial classes so we are able to do it the way mentioned above.

Now at runtime, you can create an instance of your TableAdapter like this..

SqlConnection connection;
//create the connection here at runtime..
MyTableAdapter adapter = new MyTableAdapter(connection);

or may be even assign it later after you create the TableAdapter instance with default parameterless public constructor..

SqlConnection connection;
//create the connection here at runtime..
MyTableAdapter adapter = new MyTableAdapter();
adapter.SetConnection(connection);