One of the limitations of RS version 1.0 is that it doesn’t allow you set the connnection string (a.k.a. data source) during runtime. For example, you may need to support separate databases per client and based on the logged on client you may need to redirect the user to the appropriate database.
To address this issue, Toby Riley developed an interesting dynamic query data extension which allows you to pass the connection string as a report parameter. If you don’t want to pass the connection string as a parameter, you should be able easily to retrofit the code to read the connection string from a configuration file. For more information how this could be done read my posting at http://tinyurl.com/3tcpj.
Toby’s extension is buit upon mine ADO.NET custom dataset data extension. You can download and give the Dynamic Query Data Extension a spin at http://workspaces.gotdotnet.com/appworld.
My custom ADO.NET dataset extension can be downloaded from http://www.gotdotnet.com/Community/UserSamples/Details.aspx?SampleGuid=B8468707-56EF-4864-AC51-D83FC3273FE5.