frevvo comes with a database connector that lets you create forms that read from and write to your database. Users can access any data from your database on your frevvo, and if your business rules permit it, use the forms to update or delete the data as well. The connector translates the SQL queries you run against your database into a format your Web browser can understand. Your forms access the connector via a URI that you provide in the Forms Designer.
This documentation describes the v2.2 frevvo database connector. If you are using the v2.3 database connector there are very minor changes. Please note the "v2.3 only" notes.
We strongly recommend that you also study the Database Connector Tutorial for detailed examples of using the connector. Also, the Database Connector Examples contain commonly used form design patterns using data from your database in simple examples designed to get you going quickly and give you ideas for your own forms.