From the Forena project page: use Feeds to create nodes using Forena data blocks and/or reports. In other words: Forena can be used as a feeds importer (= to enable Feeds to go read from al kinds of database tables, external databases, etc. which Feeds out-of-the-box does not support). And Forena comes with various hooks to use Forena from within another module.
For more details about Forena, 2 types of documentation are available:
The 7.x-4.x version also includes an amazing (I think) UI for either creating your reports (the WYSIWYG report editor) and/or for creating your SQL queries (the Query Builder).
Here are some variations of the external databases part mentioned above:
- Using a SQLite instead of MySQL database: the Forena samples actually get shipped including a (Tiny) SQLite database. Go check it out in the demo site: the data shown there are data contained in the sampledb, which is in SQLite format.
- Forena comes with a full suite of Supported database connections ... such as MySQL, MS SQL, Oracle, Postgress or any PDO compliant variation.
Disclosure: I'm a co-maintainer of Forena.