In order to better support sandbox servers and new functionality, the backend for the RESO Reference Server will migrate to MongoDB from Maria (RDBMS).

The main work for this change is in updating the query builder being used to create SQL queries based on OData URLs and query params.

Initially, existing functionality needs to be ported. There will be additional work needed to support things like OData $expand, nextLink, the Lookup Resource, and complex data types.

Another consideration is that the Mongo implementation needs to support the two different kinds of single and three different kinds of multiple enumerations defined in the Web API Core standards.

Ultimately the goal is to certify the reference implementation on DD 1.7 and DD 2.0, with each of the different kinds of enumerations, as well as Web API Core 2.0.0 and 2.1.0.