Create options of fieldtypes with option lists dynamically on runtime from database using sql - New in Subscription 3.4.0 Beta

Since version 3.4.0, which we have released as a Beta version, the visForms Subscription provides you with a new, often requested feature. You can create the option lists of fields of type select, radio and checkbox group now dynamically during the runtime from data stored in your Joomla! database using SQL statements. Using placeholder in the SQL Statement, for example for the current Joomla! input object values, determine whether and when to reload the option list, depending on inputs made in the form by the user and the option to hide a field with an empty option list makes this a very powerfull and flexible new feature.

You can find more information in the documentation