django-orm

Django Filter by ForeignKey value Question: Suppose I have two models class DocumentType(BaseModel): name = models.CharField(max_length=128) code = models.CharField(max_length=128) exp_days = models.PositiveIntegerField("Remind me before (Days)", blank=True, null=True) def __str__(self): return str(self.name) class Document(BaseModel): type = models.ForeignKey("masters.DocumentType", on_delete=models.PROTECT) date_of_expiry = models.DateField(blank=True, null=True) attachment = models.FileField(blank=True, null=True) def __str__(self): return str(self.employee) How can I retrieve documents with …

Django Q objects vs python code better performance? Question: What would provide better performance using filtering conditions with Q in django ORM or simply fetching unfiltered objects and comparing in python. employee_qs = employee.objects.filter(state=States.ACTIVE, topic_assn__topic_id=instance.ss_topic_id).select_related(‘c_data’).filter( Q(c_data__is_null=True) | Q(c_budget__gt=F(‘c_data__budget_spent’) + offset_amt)) V/s employee_qs = employee.objects.filter(state=States.ACTIVE, topic_assn__topic_id=instance.ss_topic_id).select_related(‘c_data’) for employee in employee_qs: if not employee.c_data or float(employee.budget)-employee.c_data.budget_spent > …

When I do "makemigrations" I get do "makemigrations" Question: I removed all migration files from my django project and now when i want to re-create i get this ./manage.py makemigrations INFO: AXES: BEGIN LOG :: [axes.apps] 2022-09-15 16:51:59,923 – /home/mixnosha/work_MVD/MVD_LTP/MVD_LTP-ltp/venv/lib/python3.10/site- packages/axes/apps.py:33 INFO: AXES: Using django-axes version 5.31.0 :: [axes.apps] 2022-09-15 16:51:59,926 – /home/mixnosha/work_MVD/MVD_LTP/MVD_LTP-ltp/venv/lib/python3.10/site- packages/axes/apps.py:34 INFO: …

How to delete all records which is 24 hours old using django ORM? Question: Model: class Question(models.Model): question_text = models.CharField(max_length=100) option1 = models.CharField(max_length=50,null=False) option1_vote = models.IntegerField(default=0) option2 = models.CharField(max_length=50,null=False) option2_vote = models.IntegerField(default=0) option3 = models.CharField(max_length=50,null=False) option3_vote = models.IntegerField(default=0) option4 = models.CharField(max_length=50,null=False) option4_vote = models.IntegerField(default=0) date_time = models.DateTimeField(auto_now=True) user = models.ForeignKey(User,on_delete=models.CASCADE) We have the date_time field …

Calculate sum of model objects in django serializers Question: In my app, each user has his wallets in which he can save his daily expenses. How can I get sum of money for each instance of wallet with many expenses saved to it? I’ve tried serializers.SerializerMethodField() from django.db.models import Sum from django.db.models import Q class …

Order Django Queryset by attribute that could be char or int? Question: I have the following model that I need to order by the grade attribute, but that attribute can be either a character or integer (K, KA, KF, NA, 1, 2, 3, etc.)… what is the best way to accomplish that? We are using …

How to make (if & else) for internal values in django orm? Question: I am making models for my store project and I wanted to know why the code I wrote is wrong? And how can I write correctly? I want only the time when a product is sold from me to be recorded in …

Auto increment rank field in my response in Django Rest Framework Question: I’ve a StudentAnswer model which stores the answer id given by the student(User) in a quiz. If the answer is correct then 1 marks else 0. The model looks like this: class StudentAnswer(models.Model): user = models.ForeignKey(User, related_name=’user_question_answer’, on_delete=models.SET_NULL,null=True, blank=True) answer = models.ForeignKey(QuizQuestionAnswer, related_name=’user_answer’, …

Django : Ignore a __in type filter in the queryset if it searches the empty list Question: Having this code sequence: queryset = self.filter( brand_id__in=( UserObjectPermission.objects.filter( content_type=brand_ctype, user=user, ).values_list(‘object_pk’) ) ) If there is no UserObjectPermission object that matches the filter content_type=brand_ctype, user=user then the end result will be empty queryset, because brand_id __in will …

How to apply filter on django ManyToManyField so that multiple value of the field follow the condition? Question: class Publication(models.Model): title = models.CharField(max_length=30) class Article(models.Model): headline = models.CharField(max_length=100) publications = models.ManyToManyField(Publication) p1 = Publication.objects.create(title=’The Python Journal’) p2 = Publication.objects.create(title=’Science News’) p3 = Publication.objects.create(title=’Science Weekly’) I want to filter articles, published in both p1 and p3. …