django-queryset

问题 TO SAVE DATA that is inputted in form in Django i tried tomake it like this I put this in my model.py class Item(models.Model): CATEGORY = ( ('Gudang Kering', 'Gudang Kering'), ('Gudang Basah','Gudang Basah'), ) name = models.CharField(max_length=200,null= True) stock = models.IntegerField(default='0', blank=False, null=True) category = models.CharField(max_length=200,null= True,choices=CATEGORY) reorderlevel = models.IntegerField(default='0', blank=False, null=True) maxreorderlevel = models

问题 this is a simple question. I'd like to know if it is the same to write: queryset = Model.objects.filter(field=None) than: queryset = Model.objects.filter(field__isnull=True) I'm using django 1.8 回答1: They are equal: >>> str(Person.objects.filter(age__isnull=True).query) == str(Person.objects.filter(age=None).query) True >>> print(Person.objects.filter(age=None).query) SELECT "person_person"."id", "person_person"."name", "person_person"."yes", "person_person"."age" FROM "person_person" WHERE

问题 I came across some strange behaviour recently, and need to check my understanding. I'm using a simple filter in the model and then iterating over the results. e.g. allbooks = Book.objects.filter(author='A.A. Milne') for book in allbooks: do_something(book) oddly, it was returning only a partial list of books. However, when using the same code and using iterator(), this seems to work well. i.e. for book in allbooks.iterator(): do_something(book) Any idea why? p.s. I did look through the Django

问题 Given the following relation: class LicenseRequest: license_type = models.ForeignKey(LicenseType) created_at = models.DateField(default=now, editable=False) class LicenseType: name = models.CharField(max_length=100) value = models.CharField(max_length=3, unique=True) I want to count how many requests have been created for each license type. However, since I am generating a graphic, I must include 0 (zero) for license types without any license request in that specific period. I tried to do

问题 Given the following relation: class LicenseRequest: license_type = models.ForeignKey(LicenseType) created_at = models.DateField(default=now, editable=False) class LicenseType: name = models.CharField(max_length=100) value = models.CharField(max_length=3, unique=True) I want to count how many requests have been created for each license type. However, since I am generating a graphic, I must include 0 (zero) for license types without any license request in that specific period. I tried to do

问题 It is needed to attach to queryset results related object field. Models: class User(models.Model): name = models.CharField(max_length=50) friends = models.ManyToManyField('self', through='Membership', blank=True, null=True, symmetrical=False) class Membership(models.Model): status = models.CharField(choices=SOME_CHOICES, max_length=50) from_user = models.ForeignKey(User, related_name="member_from") to_user = models.ForeignKey(User, related_name="member_to") I can do this: >>> User.objects.all

问题 It is needed to attach to queryset results related object field. Models: class User(models.Model): name = models.CharField(max_length=50) friends = models.ManyToManyField('self', through='Membership', blank=True, null=True, symmetrical=False) class Membership(models.Model): status = models.CharField(choices=SOME_CHOICES, max_length=50) from_user = models.ForeignKey(User, related_name="member_from") to_user = models.ForeignKey(User, related_name="member_to") I can do this: >>> User.objects.all

问题 My question is simple: in a Django app, I have a table Users and a table StatusUpdates . In the StatusUpdates table, I have a column user which is a foreign key pointing back to Users . How can I do a search expressing something like: users.filter(latest_status_update.text__contains='Hello') Edit: Please excuse my lack of clarity. The query that I would like to make is something like "Give me all the users whose latest status update contains the text 'hello'". In Django code, I would do the

问题 I have a related query of limit 10 of an object. It's taking over 9s to load the whole page in development mode. When I'm not running the related query for loop on template, it only takes 1s to load. I'm quite confused what's going on in here! Please help me identify the problem/what I'm doing wrong here! Thanks in advance! Here' my view file code - related = News.objects.filter( is_active=True, status='public', language=request.LANGUAGE_CODE, category=news.category ).order_by('-published_at'

问题 I have a related query of limit 10 of an object. It's taking over 9s to load the whole page in development mode. When I'm not running the related query for loop on template, it only takes 1s to load. I'm quite confused what's going on in here! Please help me identify the problem/what I'm doing wrong here! Thanks in advance! Here' my view file code - related = News.objects.filter( is_active=True, status='public', language=request.LANGUAGE_CODE, category=news.category ).order_by('-published_at'