2024 Django filter nested query

Django filter nested query

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August undefined, 2024

WebSorted by: 4 The structure of your contains needs to match the JSON, beginning with the first array. Each level of array in your JSON needs to be represented in the contains= It is easier to show than to say. Like this: MyModel.objects.filter ( metadata__vis__plots__contains= [ {'externalData': [ {'source': {'name': 'FINDME'}}]}] ) … WebJan 30, 2005 · Django provides F expressions to allow such comparisons. Instances of F() act as a reference to a model field within a query. These references can then be used in …

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WebJun 2, 2024 · The superfluous empty and full Q expressions ~Q () and Q () are finally optimized and eliminated by Django. Example: >>> expression = " (k=1&k=2&~k=3) ( k1 = 1 & ~ k4 = 3 )" >>> qs = queryset.filter (compile_q (expression)) Check: >>> print (str (qs.values ('pk').query)) # a simplified more readable sql print SELECT id FROM ... WebJan 31, 2024 · 1 I have a json field for a model in my Django app that typically has nested json in it. I read that to filter on a JSONfield, you would use contains on the filter for whatever value you are looking for, but I'm not getting any results back even though I know the value does exist in the JSONField. the dene woldingham

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WebDjango RawSql query to do filter on nested json Ask Question Asked 5 years, 9 months ago Modified 5 years, 9 months ago Viewed 1k times 2 My Models looks like this class Foo (): payload = JSONField () Payload looks something like this WebMay 8, 2024 · The way I am trying to test if i can query my data back is by using the search function which is as follow: def search (text): s = Search (index="comments-index").filter ("term", score= text) response = s.execute () return response. I am unable to query the nested object and have tried a lot of different methods but failed. WebThe purpose of Django RESTQL on filtering is only to generate query parameters form query arguments. For example if you have a query like. query = (age: 18) { name, age, location (country: Canada, city: Toronto) { country, city } } Django RESTQL would generate three query parameters from this as shown below. the deneway lancing

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Django RawSql query to do filter on nested json

WebAs I understand, the current prefetch_related mechanism has its usages, when one wants to prefetch a specific part of the tree and return data that only depends on that. However, what we think we need is a way to influence the queryset argument to the Prefetch instance the optimizer will use, and let the optimizer do the rest dependin on the selected fields: WebJul 20, 2024 · class SessionFilter (FilterSet): type_filter = filters.CharFilter (method="filter_by_type") def filter_by_type (self,queryset,name,value): queryset = queryset.filter (session__details__type=value).distinct () return queryset class SessionModelViewSet (ModelViewSet): queryset = Session.objects.all () serializer_class … the dene school thornabyWebFeb 27, 2024 · 1. I want to filter the nested data, and these are my serializers and views. Models : class Employee (models.Model): employee_identity = models.CharField (max_length=255, blank=True, null=True) full_name = models.CharField (max_length=255, blank=True, null=True) place_birth = models.CharField (max_length=255, blank=True, … the dene woldingham cafe

"WebNote: this answer was written in 2013 for Django 1.5. See the other answers for better approaches that work with newer versions of Django. Use isnull. users_without_reports = User.objects.filter(report__isnull=True) users_with_reports = User.objects.filter(report__isnull=False).distinct() " - Django filter nested query

Django filter nested query

WebJul 7, 2024 · The QuerySet API reference contains a section about the performance of nested queries. Performance considerations. Be cautious about using nested queries and understand your database server’s performance characteristics (if in doubt, benchmark!). Some database backends, most notably MySQL, don’t optimize nested queries very well. http://www.duoduokou.com/python/27678546271281491080.html

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WebApr 14, 2015 · class User (models.Model): username = models.CharField (max_length=255) class UserComment (models.Model): user = models.ForeignKey (User) text = models.CharField (max_length=255) How can I make a queryset in the django view in order to have a list like the following? WebThe get method consistently returns an instance of a specific model, while the filter method returns the QuerySet. QuerySet is a wrapper for a set of objects in the database. QuerySet and Manager share a lot of common, so you can undoubtedly change over one into another. You can consider QuerySet of another type of Manager.

WebJun 8, 2016 · You can create subqueries in Django by using an unevaluated queryset to filter your main queryset. In your case, it would look something like this: employee_query = Employee.objects.filter (company='Private') people = Person.objects.filter (employee__in=employee_query) WebApr 9, 2024 · Normally, in Django, using rest_framework, to add a custom field to a model, you can use SerializerMethodField.From what I understand however, this works great for values that are easy to calculate, but if the value requires database queries to related tables, you're going to be performing these for every item being returned.

WebJun 7, 2016 · You can create subqueries in Django by using an unevaluated queryset to filter your main queryset. In your case, it would look something like this: employee_query = Employee.objects.filter (company='Private') people = Person.objects.filter … WebExample Get your own Django Server. Return only the records where the firstname is 'Emil': mydata = Member.objects.filter(firstname='Emil').values() Run Example ». In SQL, the …

WebOct 28, 2024 · A Computer Science portal for geeks. It contains well written, well thought and well explained computer science and programming articles, quizzes and practice/competitive programming/company interview Questions.

WebJun 18, 2024 · To limit related offers with custom queryset you can use prefetch_related with Prefetch object: from django.db.models import Prefetch User.objects.filter (offers__description__icontains=sometext).prefetch_related (Prefetch ('offers', queryset=Offer.objects.filter (description__icontains=sometext))) Share Improve this … the denes high schoolWebNov 25, 2024 · from django_filters import rest_framework as filters class QuestionFilter (filters.FilterSet): exam = filters.IntegerField (method="filter_exam") class Meta: fields = ('category', 'exam') def filter_exam (self, queryset, name, value): return queryset.filter (answer__exam_id=value) in view the denfinition of promotional mixWebApr 20, 2024 · Then you can also do query-optimizations with select_/prefetch_related later on (if you are getting more queries). Example: class myview (...): qs = Genre.objects.filter (book_set__year__gt=1950) ... Also see the field-lookups in the docs for filtering with gt. Share Improve this answer Follow answered Apr 20, 2024 at 11:12 wfehr 2,165 10 21 the dengieWebA (possibly) better way to write the query if you're trying to avoid extra work: gateway_devices = ( GatewayDevice.objects .filter (end_date__isnull=True) .select_related ("gateway", "device") ) This will get everything in one query and you can just use simple attribute access to get the related objects without any extra queries, such as: the dengie medical partnershipWebDec 24, 2024 · This lets you define queryset to choose the set objects from. So, you would write your Menu retrieval query something like this: from django.db.models import Prefetch menus = Menu.objects.filter (is_active=True).prefetch_related (Prefetch ('categories', queryset=Category.objects.filter (is_active=True))) the dendera “lightbulb” is refuted byWebFirst, you should get familiar with the Model object manager. We will use it to get and filter the data for a particular model. Once you learn the syntax rules, you’ll be able to easily … the dengeosWebFeb 2, 2024 · To make your example work you need to replace plant_step_id for plant_step_id__plant_id and step_title for plant_step_id__step_title, because these are nested properties that are part of PlantStep not PlantLifeCalendar. However and easier way is to use Django Rest Framework Filtering Guide. First install pip install django-filter. the dengie hundred