Open AI - Database

I am using the new Open AI Assistant. I want to upload a screenplay to be analyzed by Open AI. I have been able to upload and parse the file to a text. However I’m not sure how to access the database to send the text to Open AI. The idea is, instead of typing the question into a field, it grabs the text from a database. I have set up API Connector and configured Open AI: Create Assistant, Create Threads, Create Messages, Create Run, Get Run, and List Messages. I’m just not sure of the workflow. Is there anyone who can help?