Feature Request: Add support for DuckDB

[DeflateAwning]

I see that you have support for SQLite, but I think it would be awesome if you added support for DuckDB, an alternative OLAP database that looks and feels very similar to SQLite.

It already has a Rust API, and has r2d2 support (not sure if that's really helpful, but figured it was worth mentioning).

[weiznich]

We do not plan to add any more backends/database connection implementations to diesel itself anymore. We are already at the limit on what we can maintain as project therefore we just don't have the capacity for more connection implementations.

Fortunately it's possible to just implement such a custom backend/connection outside of diesel, with essentially the same level of functionality as it would have as if it were implemented in diesel itself. You might want to consult the documentation on this topic or checkout existing third party implementations like diesel-oci (oracle database) or rsfbclient-diesel (firebird database). If you choose to go down that route we are happy to provide some more detailed pointers about how to approach such an implementation.