Question

I am developing an application in Django and I am curious on how I can go about adding a model such that only 1 row is only ever present (i.e. Singleton).

As an example, I’d like to maintain a set of boolean flags of the application i’m running as to whether: it’s on or off (so I can manually turn it on or off, perhaps even per module).

I can’t see any part of the docs explaining a good way to go about setting this up.

Any suggestions?

Answer 1

Not sure from you explanation in what context you require this but I have a model which holds a number of key/value pairs used in validator checks and other things. The keys are all needed by each implementation of the project but the values will differ between projects. The values should be maintainable by an admin user. The values usually do not need to change very much once set. Given that, I decided to put them in a model. It is a bit weird but simple enough.

1. You should be able to limit write access to the model to the one row for either your app or your users through your code.

2. only ever reference the first row in the QuerySet

   row = MyVariables.objects.all()[0]
   

Test if there are rows first. if you think there might accidentally be more than one record then make sure it is ordered (but that should never happen if you did (1) correctly.