If you mean Silverlight from Microsoft (Microsoft Silverlight) it's not a database, although you can add code so you can interact with a database. The place you need to connect is the data source behind that, maybe a MSSQL Server?
Is there a REST or SOAP type API that returns XML, CSV, JSON?
If so you can use the Web File data connection.
Take a look at this video if interested: Data Load Editor - Loading Web Data (video)
Hi David - you may also be interested in QVSource - to see if their list of data connectors can provide what you need.
You can see and example here: Qlik Sense Desktop - Using QVSource Data Connectors (video)