Tag: django-models

How can I set two primary key fields for my models in Django?

django django-models model primary-key python

I have a model like this: How can I have the primary key be the combination of migration and host? Answer Update Django 4.0 Django 4.0 documentation recommends using UniqueConstraint with the constraints option instead of unique_together. Use UniqueConstraint with the constraints option instead. UniqueConstraint provides more functionality than unique_together. unique_together may be deprecated in the future. Original Answer I

Django – how to create a file and save it to a model’s FileField?

django django-models python

Here’s my model. What I want to do is generate a new file and overwrite the existing one whenever a model instance is saved: I see lots of documentation about how to upload a file. But how do I generate a file, assign it to a model field and have Django store it in the right place? Answer You want

Django: override the save() function of an abstract model

django django-models python

I have tried to override the save() function on a model that is abstract, and am getting an error So if possible, how do you override the save function on an abstract model. The model that extends from this is Entry Here is my model Code: (For those who are familiar, I am extending the Entry model on the zinnia-blog,

How do I filter query objects by date range in Django?

date-range django django-models django-queryset python

I’ve got a field in one model like: Now, I need to filter the objects by a date range. How do I filter all the objects that have a date between 1-Jan-2011 and 31-Jan-2011? Answer Use Or if you are just trying to filter month wise: Edit As Bernhard Vallant said, if you want a queryset which excludes the specified

How can I store an array of strings in a Django model?

django django-models python

I am building a Django data model and I want to be able to store an array of strings in one of the variables; how can I do that? e.g. Thanks for the help. Answer Make another model that holds a string with an optional order, give it a ForeignKey back to myClass, and store your array in there.

How to limit the maximum value of a numeric field in a Django model?

django django-models django-validation python

Django has various numeric fields available for use in models, e.g. DecimalField and PositiveIntegerField. Although the former can be restricted to the number of decimal places stored and the overall number of characters stored, is there any way to restrict it to storing only numbers within a certain range, e.g. 0.0-5.0 ? Failing that, is there any way to restrict