Database System for Manual Entry

I'm in charge of setting up a patient register (100K+ patients) for a non-profit project with little money. This register should provide the basis for later datascience. I'm not sure how a good database solution can work the long run. It must be possible for various clinics to enter the data manually into the system. Since I have experience with Django I have developed a webapp prototype with Django and an SQLite DB (it is not expected that many users access the database at the same time). But I'm not sure what kind of database would be a good a good choice in the long run. The biggest problem is that a self-made solution may be beautiful for the moment but it binds the project to me and thus puts it in danger in the long run (the typical doctor doesn't know much about programming). My question is basically about experiences of you experienced datascientists like you for suitable databases and solutions.