Django:两个来自不同数据库的模型

I am new to Django; I have a legacy database I do not control with some information regarding a user and a database on my server with data pertaining to something that user is doing. I want to take some information from each database via the ORM methodology Django employs and display it on a webform, but I am struggling. I search on the patient id and can find what codes they have associated with them, but when it comes to displaying the cost for each code with the associated data, I do not know the best way to do so. I am not saving this data at the moment.I am new to Django; I have a legacy database I