When I use UI Designer, i want to create a single form and communicate with database, i mean my external database and it can be accessed by an anonimous user in public.
Have a look at this helper project by Philippe of Bonitasoft.
https://github.com/Bonitasoft-Community/rest-api-sql-data-source/releases/tag/1.0
regards
Seán
PS: If this reply answers your question, please mark a resolved.