How do I run an update and select statements on the same queryset rather than having to do two queries: – one to select the object – and one to update the object The equivalent in SQL would be something like: update my_table set field_1 = ‘some value’ where pk_field = some_value 7 Answers 7
I am trying to filter a DateTimeField comparing with a date. I mean: MyObject.objects.filter(datetime_attr=datetime.date(2009,8,22)) I get an empty queryset list as an answer because (I think) I am not considering time, but I want “any time”. Is there an easy way in Django for doing this? I have the time in the datetime setted, it … Read more
I am attempting to filter users by a custom field in each users profile called profile. This field is called level and is an integer between 0-3. If I filter using equals, I get a list of users with the chosen level as expected: user_list = User.objects.filter(userprofile__level = 0) When I try to filter using … Read more
In Django, what’s the difference between the following two: Article.objects.values_list(‘comment_id’, flat=True).distinct() vs Article.objects.values(‘comment_id’).distinct() My goal is to get a list of unique comment ids under each Article. I’ve read the documentation (and in fact have used both approaches). The results overtly seem similar. 4 Answers 4
What is the recommended idiom for checking whether a query returned any results? Example: orgs = Organisation.objects.filter(name__iexact=”Fjuk inc”) # If any results # Do this with the results without querying again. # Else, do something else… I suppose there are several different ways of checking this, but I’d like to know how an experienced Django … Read more
I’ve got a field in one model like: class Sample(models.Model): date = fields.DateField(auto_now=False) 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? 8 Answers 8
When I ask the model manager to get an object, it raises DoesNotExist when there is no matching object. go = Content.objects.get(name=”baby”) Instead of DoesNotExist, how can I have go be None instead? 20 Answers 20
This question already has answers here: How can I see the raw SQL queries Django is running? (21 answers) Closed 7 years ago. How do I get the SQL that Django will use on the database from a QuerySet object? I’m trying to debug some strange behavior, but I’m not sure what queries are going … Read more
I want to write a Django query equivalent to this SQL query: SELECT * from user where income >= 5000 or income is NULL. How to construct the Django queryset filter? User.objects.filter(income__gte=5000, income=0) This doesn’t work, because it ANDs the filters. I want to OR the filters to get union of individual querysets. 4 Answers … Read more
I’m sure this is a trivial operation, but I can’t figure out how it’s done. There’s got to be something smarter than this: ids = [1, 3, 6, 7, 9] for id in ids: MyModel.objects.filter(pk=id) I’m looking to get them all in one query with something like: MyModel.objects.filter(pk=[1, 3, 6, 7, 9]) How can I … Read more
