How to fix mongo odbc 1.1 access denied for user in Challenge and Response

When supporting developers during setting up BI Connector and the ODBC System DSN for connection to a MongoDB  , a common problem is the incorrect application of the  username format , leading to a "Access is Denied" error message. What should the correct username format be for the Challenge and Response method?

Step 1 is setting up the BI Connector. Typically the developer initiated the command line utility mongosqld . The mongosqld command line utility  accepts incoming requests from a SQL client (or ODBC DSN setup used by the SQL Client)  and acts as a proxy for the incoming requests.I The proxy redirects the requests to the mongod or mongos server instance

Once Step 1 is achieved - we move onto setting up the ODBC System DSN setup . If the developer chooses to use the the Challenge and Response authentication method  aka SCRAM-SHA-1 authentication method - special attention is required to complete the username.   The common mistake is to just place the username. This results in an authentication error - "Access is denied".    To get this working write the username in the following format.

bob?source=test

For a more detailed instructions use this link to the MongoDB documentation. Create a System DSN