In my admin, I am getting errors for only one class, ‘unicode’ object has no attribute ‘utcoffset’. I have looked at a few other similar questions and have been unable to solve it. Any ideas on how to fix it? The traceback is below the class. Traceback: Answer The default value for you…
Tag: django
how django ‘auto_now’ ignore the update of specified field
i have a model, like this: name = models.CharField(max_length=255) modify_time = models.DateTimeField(auto_now=True) chasha = models.CharField(max_length=255) stat = models.CharField(…
null value in column “last_login” violates not-null constraint
Having issues getting rid of this error. I’m trying to use Digital Ocean to deploy my Django app. I configured Postgres, but when I’m trying to register a new user in my app, I get this problem. I’…
A query with 3 tables in django
I have 3 classes like this: My question is: How can I make a query to get the devices used by the person “name”? Which needs to pass through the uses class. Answer Life will be easier if you use ManyToManyField, i.e. add this field to the Person model: Then, to get the list, you just need to get t…
How can I temporarily disable a foreign key constraint in MySQL?
Is it possible to temporarily disable constraints in MySQL? I have two Django models, each with a foreign key to the other one. Deleting instances of a model returns an error because of the foreign key constraint: Is it possible to temporarily disable constraints and delete anyway? Answer Try DISABLE KEYS or …
Django: Adding “NULLS LAST” to query
I would like to sort a model by using Postgresql’s “NULLS LAST” option. How could it be done? I tried something like MyModel.objects.all().extra(order_by=(‘-price’, ‘NULLS LAST’)) But I get “Cannot resolve keyword ‘NULLS LAST’ into field” Answe…
Filtering Django Query by the Record with the Maximum Column Value
Is there an easy way to filter a Django query based on which record has a max/min value in a column? I’m essentially asking these questions, but in the specific context of Django’s ORM. e.g. Say I have a model designed to store the historical values of everyone’s phone numbers. with the reco…
django: datediff sql queries?
I’m trying to do the equivalent of the following SQL in Django: SELECT * FROM applicant WHERE date_out – date_in >= 1 AND date_out – date_in
How come queries aren’t being added to Django’s db.connection.queries in tests?
I’m trying to capture the queries which my code submits to the database by examining the contents of django.db.connection.queries. For some reason though, after all the automatically produced setup queries are logged, no further queries are logged from my own code. The following test case demonstrates t…
Aggregating save()s in Django?
I’m using Django with an sqlite backend, and write performance is a problem. I may graduate to a “proper” db at some stage, but for the moment I’m stuck with sqlite. I think that my write performance problems are probably related to the fact that I’m creating a large number of ro…