Is there a synchronized way to validate models in Django?

Question

I have a Django model called TimeSpan with a start_datetime and end_datetime field, and I want to do validation on the model so that no two TimeSpan objects overlap.

However, if I wrote code like below,

if timespan.is_valid():
    timespan.save()

then there could be a race condition where two TimeSpan objects are deemed valid compared to what is currently in the database, and then they are both saved despite being invalid together.

I could make a synchronized validate_and_save() method with locks, but that would break the Django admin. Is there an alternative built into Django?

Answer 1

You need to use transactions if you head down this direction, however I would suggest that you look at your database's trigger functionality instead...