RethinkDB has joins and I found its grouping to be straightforward and super powerful. Selecting distinct values is as simple as putting .distinct() at the end

RethinkDB has joins and I found its grouping to be straightforward and super powerful. Selecting distinct values is as simple as putting .distinct() at the end of your ReQL. While it doesn't have foreign keys, any value can act as one as long as it holds a tables primary key (or other indexed fields), in which case you can do db.table('other_table').get(primary_key_val) (or getAll(foregin_key_val, {index: 'my_index'}) if not the PK, but otherwise indexed). Granted, it won't validate that the keys exist, however (since its schemaless at the DB level), so nothing will prevent you from inserting a document with foreign keys that are invalid, but from a querying point of view, foreign keys are easy. Would be nice if you could set insert/update-checked constraints though.