Django queryset isnull. none() # doesn't hit the db Model.

Django queryset isnull filter(Income__isnull=True) Oct 16, 2015 · I have a queryset that I am ordering by -DateTimeField model: class QuestSubmission(models. B. filter(income__gte=5000) | User. from django. Filters，可以根据给定参数缩小查询结果量。 Apr 24, 2015 · これは簡単な質問です。それが同じことかどうか知りたいのですが：queryset = Model. Django's queryset objects are lazy evaluated and you can filter or do other things in separate lines. The two data models to represent this are: class Link(models. filter(user__isnull=False) . The two previous answers to this post are incorrect as Apr 17, 2016 · I have a reddit-like Django app where users can post interesting urls (links) and then publicly comment under them. i need some help writing params and ret Aug 11, 2021 · There is actually a django SQL operator to exclude null values. What's the problem with this solution? Could it be in your data? As a sanity check you could try . filter(some_field__isnull=False) # Obtaining all rows with field value greater than some value Model. exclude(alias__isnull=True) Here were filtering all the values from MyModel model, which have an alias = Null. Mar 9, 2014 · I'd like to get a QuerySet (to feed a ModelChoiceField) listing all objects that have an empty ForeignKey on the related set. filter(Q(pk__in=[]) # doesn't hit the DB Model. Feb 27, 2017 · Django: filtering queryset by 'field__isnull=True' or 'field=None'? 0. __isnull lookup expects boolean values in many places and IMO it would be confusing if we'll allow for truthy/falsy values, e. SELECT `books_book`. Take a look at this example: May 3, 2013 · I have to filter a queryset by a dynamic value (which can be None): may I simply write: filtered_queryset = queryset. Jan 17, 2025 · はじめに. 오늘 포스트는 유튜브 pycon 코리아에서 발표된 내용을 를 기반으로 쿼리셋에 대한 특징, 최적화 등을 다룰 것이다. models import Q import operator argument_list = [] # categories_selected = all the categories that have been checked on the page for c in categories_selected: # categories_filtered = all the (selected) categories that have filters applied if c not in categories_filtered: # Here we get all where <category>_id is defined argument Oct 6, 2023 · Django is powerful and popular web framework for Python that comes with built-in Object-Relational Mapping (ORM) system. type_gtmax == None and showtimes. exclude(alias__isnull=True). If you find yourself working with Django models but need to ensure the dataset you retrieve contains (or doesn’t contain) empty or NULL values for a field, Django has you covered. FilterSet): seen = filters. But if you don't want to mess with it here is some examples: # Obtaining all non-null fields Model. filter(field__isnull=True) else: filtered_queryset = queryset. dev20220923141503 and have adapted and extended Tim 's test a bit: def test_ticket_2361(self): """ Prove that QuerySet. exclude() with isnull=True. For example, our application has a Book model with a few basic fields: title, author, and date_published. Jun 7, 2019 · Bit more complicated way of acheiving this result is to annotate the value of sE and sB to the queryset, like this: from django. 在本文中，我们将介绍Django QuerySet中如何使用field__is_null来过滤FloatFields。Django是一个强大的Python Web框架，提供了许多功能来简化Web应用程序的开发。其中，QuerySet是Django的一种查询数据的方式，可以用于对数据 Using Django 1. BooleanFilter(field_name="seen_at", lookup_expr="isnull", exclude = True) From Django Filter Reference Docs: exclude. filter(bars__isnull=False) But this will only be ordered by the default order of Foo date. models import Count models. models. Ce document détaille l’API des objets QuerySet. An example extract of my models: class Bankcard(models. Feb 22, 2011 · Question about how to perform a django query. 4 rc1. Deploy Django Elastic Beanstalk (EB) Create requirements. Ces trois QuerySet sont séparés. Django QuerySet：是否可以使用field__is_null过滤FloatFields. filter(field__isnull=True) Django 1. exclude(Q(alias__isnull=True) | Q(alias__exact='')) 有关更多信息，请参阅 此页面 和Django 文档中的 此页面。 顺便说一句：我的 SQL 示例只是一个类比——实际生成的 SQL 代码可能看起来不同。 The initial QuerySet (q1) is unaffected by the refinement process. exclude(field=None) Dec 16, 2020 · I have this queryset: output = self. titleもauthorもNullのBookを引っ張ってくる場合. CharFilter(lookup_expr='iexact') field1__isnull = django_filters. objects The initial QuerySet (q1) is unaffected by the refinement process. Dec 24, 2014 · empty = TestModel. 8 or later: Oct 16, 2022 · Django developers can use . filter (title__isnull= True Jan 9, 2017 · I am using Django REST Framework in project and I want to create union two different Models. filter(some_field__isnull=False, some_field__gt=value) # Actually the better way of writing complex Feb 9, 2015 · Now I want to have a function that takes in that queryset object and filters the results further based on some other attributes, something like this: def is_subtitled_3d(showtimes): return ( showtimes. language == LANGUAGE_SUBTITLED and showtimes. models import Q # 空文字列または NULL の名前を持つレコードを除外 queryset = MyModel. Share. `id`, `books_book`. filter(field=None) than: queryset = Model. Il augmente les contenus présentés dans les guides des modèles et des requêtes de base de données, il est donc conseillé de lire et de comprendre ces derniers avant de lire celui-ci. filter (size__isnull = True) 完全一致(大文字小文字区別有り)でレコードを取得 annotate() ¶ annotate (*args, **kwargs) ¶. isnull: Matches null field values. ) that has been computed over the objects that are related to the objects in the QuerySet. values( 'label', 'minutes_allotted', 'days_to_complete', 'pk', number_of_children=Count('children') ) It does the job. order_by 直接按照字段排序 Since Django 1. This organisation has multiple rooms each with storage sections on shelves. Le premier est un QuerySet de base contenant tous les enregistrements qui contiennent un titre commençant par « What ». That is, when null=True and blank=True in the model as mentioned in the start post Jun 5, 2022 · There is a whole section in Django documentation related to model field lookups. ) Dec 11, 2023 · 1105👍 You could do this: Name. RnD_id__isnull=False)), all_hours=Sum('hours_worked')) return Dec 24, 2014 · If you look at the full query, you will see that Django does two Left Outer Joins from the foo table to the joining table foo_bar and to the bar table. clisten_: 博主，mongo数据库使用该bulk_reate方法报错： 'QuerySet' object has no attribute 'bulk_create' django 限定只能是post请求访问视图 200317. exclude(Q(name= '') | Q(name__isnull= True)) 解説 Q オブジェクト 複数の条件を組み合わせたフィルタリングを可能にします。 May 10, 2009 · from django. (It does provide a query lookup, but it may only be used for filtering. Feb 27, 2023 · class MessageFilterSet(filters. views import generic from . Is there a way to use isnull here? I've tried: Mar 17, 2020 · django QuerySet bulk_create方法 200316. ForeignKey(User, related_name='%(class)ss') __unicode__ = lambda Jul 10, 2016 · class CurrentDealsView(ListView): model = models. QuerySet s are lazy¶ QuerySets are lazy – the act of creating a QuerySet doesn’t involve any database activity. exclude(substance_points__isnull=True). Jul 4, 2023 · In Django, a QuerySet is a collection of database objects that have been retrieved using a query. filter 오늘은 Django ORM 중 쿼리셋(Queryset)에 대해서 다루어 보려고 한다. Consider two foos and two bars . b = ABWrapper. distinct('user'), but that works only on some database back ends. config Create . NULL Values: In a database, a NULL value signifies the absence of a value. Jul 19, 2019 · So for this, the Django docs around querysets and q objects will be your friend. Read through the discussion, it is interesting. `title` FROM `books_book` WHERE `books_book`. Deals def get_queryset(self): #get all the deals having started in the past or today and closing in the future or today now = datetime. order_by('-income') Update 2019-06-20: This is now fully documented in the Django 2. Annotations are different to aggregations, as annotations are applied to every result in the queryset. (Session. Model): # other misc game-description fields Jul 3, 2017 · from django. In this brief tutorial we’ll explore the simple methods and chain functionality Django offers to make model filtering of fields a breeze. models import Question, Choice from django. models import ExpressionWrapper, Count, Value, DecimalField Contract. ForeignKey(settings. django的各种查询语句: filter, exclude, annotate等. filter(m2mfield__isnull=False) may return duplicates. utils import timezone class DetailView(generic. """ import copy import operator import warnings from itertools import chain import django from django. db import models import django_filters class Mymodel(models. Mar 24, 2020 · Filtering empty or NULL values in a Django queryset . now() start_date_condition=Q(start_date__lte=now) end_date_condition = Q(end_date__gte=now) | Q(end_date__isnull=True) #get all the deals with a number of Jun 10, 2015 · from django. 0 Mandatory impostor syndrome notice: The documentation has gotten a lot easier to navigate and this cheatsheet makes a lot less sense nowadays, but many people seem to be actively using it, so i'll keep it updated for a few more versions. annotate(gcount=Count('groups'). filter(gcount__gt=0) which should yield the same results. Return all not null values if False. all() if var1: family_queryset = family_queryset. I would like to be able to create a filter for the ListingReview model, so that people can select which Listing they want to see reviews for. distinct() May 31, 2021 · You can annotate the value of OuterRef('baz') and use that in your filters. More historic discussion can be found in DjangoProject ticket #21333. 12. 8 I'm trying to filter a model on whether only exactly one of the chosen fields are populated. It is remarkable because (as of April 2016) it was "opened 9 years ago" (in the Django stone age), "closed 4 years ago", and "last changed 5 months ago". filter(foo=var1) if var2: family_queryset = family_queryset. filter( # work around to force left outer join Q(trackhastag__isnull=True) | Q(trackhastag__isnull=False) ). Case( models. 0 to make sure of that: from django. filter(field=None) より：queryset = Model. I'd like to know if it is the same to write: queryset = Model. You can stack filters together all day long, and Django won’t actually run the query until the QuerySet is evaluated. Django queryset: Exclude all row(s) if any one Oct 8, 2016 · For your reference use Django Filter doc. Defaults to False. ついでにAnd検索、Or検索についてメモ. Let foo_1 be related to bar_1 and bar_2 , and foo_2 not be related to any bars . QuerySet API [ ] annotate. Also it looks like filtering on the annotated OuterRef will not work because of this bug having Ticket #31714, but we can get around that by using an ExpressionWrapper to manually specify the output_field. 0. 在本文中，我们将介绍在Django中如何使用’field__isnull=True’或’field=None’来过滤查询集。这两种方法在实际开发中经常会遇到，通过了解它们的用法和区别，我们可以更好地理解和应用Django的查询功能。 Current Django Version: 5. filter(b__isnull=False). db. count() Or you can use conditional expression. txt Create django. Easily the most important method when working with Django models and the underlying QuerySets is the filter() method, which allows you to generate a QuerySet of objects that match a particular set of filtered parameters. May be following example useful. annotate? May 4, 2014 · You only want Foo object that have a Bar object linked to them, that mean: filter. posts=Post. "id" <> %s or "app Jan 19, 2015 · First, I use annotate to add the summary to the queryset: You can use Django's Coalesce function. Jun 3, 2015 · Django doesn't support the select_related() method for reverse foreign key lookups, so the best you can do without leaving Python is two database queries. DateTimeField(auto_now=True) Author = models. user, time_completed__isnull=True) Share Jan 27, 2019 · I'm building an inventory management app for an organisation in Django. Example 2: Using Q Objects for More Complex Filtering. db import (DJANGO_VERSION_PICKLE_KEY, IntegrityError, NotSupportedError, connections, router, transaction,) from django. 起航吧！ I was able to reproduce the problem in Django 4. models import F TSF. If you want to get their counter part not_empty = TestModel. Take a look at this example: from django. One common task when working with databases in Django is filtering QuerySets to retrieve only the records that meet certain criteria. Feb 18, 2025 · Chaining exclude() By chaining these two exclude() calls, we ensure that the final queryset only contains objects with non-NULL and non-empty name fields. AUTH_USER_MODEL, Django 空ImageField上的Filter Queryset 在本文中，我们将介绍如何在Django中过滤空的ImageField的Queryset。ImageField是Django模型中用于存储和处理图像的字段之一。我们将探讨如何使用__isnull运算符以及自定义查询过滤器来过滤具有空ImageFied的记录。 Dec 9, 2015 · I am looking for a single queryset, which gets me objects of C for specific fieldOfA or specific fieldOfB values. Apr 6, 2023 · QuerySets allow you to retrieve a list of objects from a database table that meets certain criteria. Django’s serialization framework provides a mechanism for “translating” Django models into other formats. models annotate() ¶ annotate (*args, **kwargs) ¶. FilterSet): field1__iexact = django_filters. Apr 25, 2015 · this is a simple question. Also you cannot use a Subquery as queryset parameter to Prefetch, unfortunately. CharField(max_length=255) field2 = models. In Django queryset we have __isnull to check if a value is null. filter(invoice__isnull=True) Here, you've specified the related_name attribute, so you need to use that: Income. `title` IS NULL. filter(field=value) Does the behaviour depend on the particular DBMS? Nov 18, 2014 · I want to be able to query a model for records where the is no value for a particular float field. MySQL doesn't seem to support it. filter(submitter=user, publicreply__isnull=False) Share. filter(photo__isnull=False). I tried this, but it fails (returns [], despite there being valid results). Aug 23, 2013 · Normally, Django automatically follows relationship fields using the lowercased name of the related model: Income. This provides the public API for the ORM. 0) / (Count('pk') * Value(1. . filter(field__isnull=True) I'm using django 1. objects. distinct() using exclude instead of filter and using the True boolean arg. extra( # where parameters are “AND”ed to any other search criteria # thus we need to account for NULL where=[ '"app_trackhastag". filter(field!=None) # If you insist on the second way queryset = Model. type_3d == 1 and showtimes. django will create a field with label of the attribute time_completed but you just filter like this todos = Todo. The first point to make is null != '' in SQL they are two different values. Hope this could be of some help! Jan 8, 2019 · I want a QuerySet containing a has_user field that would basically map to the following SQL query. annotate( duration=models. 8 Django provides a range of QuerySet refinement methods that modify either the types of results returned by the QuerySet or the way its SQL query is executed. Improve this answer. Jan 21, 2015 · Unfortunately, Django doesn't provide function IsNull, that could be used for ordering, annotations, etc. `author_id`, `books_book`. When( Q(started__isnull=False Yes it does, the following two ways render the same count(): (1) using the django. Student. Model): field1 = models. As you say, the resulting queryset will return each post once for every photo which is attached to it. exclude(alias__exact='') Chaining these methods together basically checks each condition independently: in the above example, we exclude rows where alias is Jul 8, 2021 · I'm trying to customize isnull lookup to return both null and blank values and django documentary doesn't give enough inforamtion about how exactly it works. When Querysets Are Evaluated Methods that return new Querysets 返回Queryset的方法 . field_b__isnull=True, field_c__isnull=True, field_d Oct 19, 2021 · Django 逆引き(QuerySet) 2021/10/19 posts = Post. 要从数据库检索对象，要通过模型类的 Manager 构建一个 QuerySet 。 一个 QuerySet 代表来自数据库中对象的一个集合。它可以有 0 个，1 个或者多个 filters. May 23, 2017 · I know this thread is old, but using simplejson to convert django models doesn't work for many cases like decimals ( as noted by rebus above). filter(mycolumn__isnull=False) To filter a Django SQL JSON field to exclude any JSON dict that has an outer level total key with a value of 0 use. eg: Player. Djangoの汎用ビューを活用する際、get_querysetとget_context_dataはデータ処理とテンプレートへのデータ渡しをカスタマイズするために非常に便利なメソッドです。 Oct 16, 2019 · I have models: class Inote(IDeclaration): Time = models. As an aside: My SQL examples are just an analogy--the actual generated SQL code will probably look different. aggregate(perc=ExpressionWrapper( Count('pk', filter=Q(verified_date__isnull=False)) * Value(1. And: Jul 4, 2018 · What about queryset extras? They do not break ORM and can be further filtered (vs RawSQL) from django. 橙子哈哈哈~: 为啥我设置post访问会是403. annotate() . #Views - assume double underscore in the query from django. You cannot annotate a queryset with another queryset, values must be field equivalents. Take a look at this example: Sep 2, 2024 · In this article, we will explain how to filter such fields in a Django QuerySet, with examples. Book. Data can be grouped by applying values() to the queryset before applying . filter(float_field__is_null=True) returns the fol They differ in one major part though: field==None is NOT reversible while field__isnull=True is. CharFilter(lookup Jul 1, 2015 · The query optimizer handles Q(pk__in=[]) better than Q(pk__isnull=True). objects . 발표된 내용이 정말 유익해서, 발표 내용과 내가 분석한 내용들을 토 Dec 30, 2020 · Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand Django：Django的查询集过滤器中的filefield非空 在本文中，我们将介绍如何使用Django的查询集过滤器来筛选filefield字段不为空的对象。 通常，filefield字段存储了上传文件的路径或URL，我们希望能够轻松地找到已上传文件的记录，以进行必要的操作。 Jan 15, 2020 · Q() is often used as a starting value for building complex lookups with Q objects. Feb 3, 2020 · You need to make the values decimal before dividing them, just multiply by 1. exclude(groups__isnull=False). annotate() to add fields to querysets and/or group the data. core import exceptions from django. filter(income__isnull=True) ordered_queryset = combined_queryset. Apr 29, 2018 · I am using Django-Filter library. models import Q Track. models import Q Name. exclude(Q(name__isnull= True) | Q(name= '')) Jun 2, 2024 · Django QuerySet Field Lookups. filter(parent=task, user=user). type_xd Jan 10, 2018 · If I use the QuoteIndexResource on its own the filter on the querysetworks but if it is pulled into RequestsResource then the filter doesn't have any effect on the data. 8を使用しています The initial QuerySet (q1) is unaffected by the refinement process. Le second est un sous-ensemble du premier, avec un critère supplémentaire qui exclut les enregistrements dont le champ pub_date est aujourd’hui ou dans le futur. Annotates each object in the QuerySet with the provided list of query expressions. After the reconsideration I don't think that we should change this documented behavior (that is in Django from the very beginning). filter(manytomany__isnull = False) Basically, you get two query sets: one where your manytomany fields are empty, and the other with objects that have data in the manytomanyfield. exclude(b__isnull=True). take a look at these examples field__isnull='false' or field__isnull='true' (both would return the same result). zip File Deploy with EB Update Project More Django Add Slug Field Add Bootstrap 5 Django References Template Tag Reference Filter Reference Field lookups Reference Django Exercises Django Compiler Django Exercises Django Quiz Django Syllabus Django Study 初めて QuerySet が評価されたとき、つまりデータベースへのクエリが発生したとき、Django はクエリの結果を QuerySet のキャッシュに保存し、明示的に要求された結果 (例えば、 QuerySet が繰り返し処理されている場合は次の要素) を返します。 Django：通过’field__isnull=True’或’field=None’来过滤查询集. filter(manytomany__isnull = True) #. Django queryset has no attribute when using select related. But I'm really only using it to check if an object has children (I don't really care about how many it has). Django filtering based on optional Mar 2, 2025 · What is the best and most efficient Django ORM approach to filter objects while excluding those that are already assigned? Would values_list(), isnull=False, or Subquery() be the recommended way? Are there any performance considerations when working with large datasets? It is not necessary. To make usage more explicit, I’d like to add the following special values: An “always satisfied” condition: Q(True) An “always unsatisfied” condition: Q(False) An “empty” operation that defaults to no Aug 15, 2018 · I have made it work by changing the query annotation to the following: sprints = Sprint. Field lookups are a way to specify conditions or constraints on the fields of the objects you want to retrieve from the Jan 31, 2014 · Django : Get queryset with filters over list (filled and/or empty) 0 Django QuerySet filtering not working with views, showing blank view even though there are entries Jun 13, 2012 · Book. As an example: # You can do this queryset = Model. none() # doesn't hit the db Model. 4 brings some changes to filters, I thought I save someone the time I just spent modifying the code from Cerin's accepted answer to work with Django 1. Model): quest = models. filter(email__isnull=True) Feb 15, 2021 · You don't have to do it in one line. filter(photo__isnull=True) Later in your question you are using isnull=False. models import Q queryset = MyModel. objects. Feb 18, 2025 · from django. Here is how it looks: MyModel Feb 23, 2021 · I would like to ask how I can drop data from the QuerySet when the value of the attribute is null. Foo. Feb 22, 2017 · The Django issue tracker has the remarkable entry #5763, titled "Queryset doesn't have a "not equal" filter operator". exclude(Q(alias__isnull=True) | Q(alias__exact='')) For more info see this page and this page in the Django docs. class Game(models. To filter out Empty values we can exclude also. You should also have a look at prefetch_related which can, unlike select_related do lookups across reverse ForeignKeys , albeit with a separate query for each element of the queryset. Checking if something is null or '' (empty) is a little tricky at first but once you understand SQL and Django ORM it will get easier. Model): descrip Mar 22, 2018 · users = User. filter(field__isnull=False) # But you can't do this queryset = Model. Link. Django queryset filter model attribute against other model attribute. May 7, 2011 · posts=Post. combined_queryset = User. QuerySets allow you to perform various operations on the data, including filtering, ordering, and manipulating the results. ForeignKey(Quest) user = models. Luckily, Django's queryset lets you filter on subqueries. The problem is the basic query: Model. conf import settings from django. Field lookups are how you specify the meat of an SQL WHERE clause. filter(Q(pk__isnull=True)) # hits the DB If even works with complex queries and tilde negation: When you use isnull=False, the distinct() is required to prevent duplicate results. 0)), output_field=DecimalField())) Oct 8, 2016 · To exclude empty user fields, filter by isnull. Model): na Aug 20, 2015 · A. g. In Django, we can allow a field to store NULL by setting null=True in the model definition. filter(last_activity_gte=time_window) . What is a QuerySet in Django? In Django, a QuerySet is a list of objects from a database table that match certain criteria. I have a Game model with a 'through' ManyToManyField to the User model. django 查询条件 包含查询contains 200316. Note These methods do not run database queries, therefore they are safe to run in asynchronous code , and do not have separate asynchronous versions. filter (title__isnull= True) 発行されるSQL. For example: Model. family_queryset = ModelClass. exclude(email__isnull=True) If you want to get all the columns with empty email value then use users = User. filter(bar=var2) Apr 22, 2011 · As skyl pointed out, this is the same as models. django filter when the some of the arguments are null. models import Q my_query = C. Here is how we use it: MyModel. Q object with an excluded filter ~Q() (2) using . Replying to felixxm:. As stated in the django documentation, serializer looks like the better choice. DetailView): model = Question template_name = 'polls/detail. type_vip == None and showtimes. select *, user_id is not null as has_user from app_testmodel How can I explain this has_user field to Django when using QuerySet. 1 QuerySet API reference. filter(user=request. Sep 2, 2024 · In this article, we will explain how to filter such fields in a Django QuerySet, with examples. Since you need to perform OR conditions you would need to use Q objects [Django docs]. An expression may be a simple value, a reference to a field on the model (or any related models), or an aggregate expression (averages, sums, etc. filter(Q(classA _ _isnull = False, classA _ _fieldOfA annotate() ¶ annotate(*args, **kwargs)¶. Dec 28, 2017 · Photo. filter(closed_date__isnull=True) work in this scenario?. I have 2 models, Listing and ListingReview. django的各种过滤方法: in, exact, contains等. Is there a way to make the . 2. values('b__id QuerySets をpickle化したデータは、生成したDjangoの同一バージョンでのみ有効です。DjangoのバージョンNで生成したデータをバージョンN+1でも正常に読み込める保証はありません。Pickle化は長期的なアーカイブ戦略の手段として用いるべきではありません。 Django 会在添加或指定错误类型的对象时报错。 检索对象¶. values_list('user_id', flat=True)) To remove duplicates, you can use . 2. To only include each post once in the queryset, use distinct. QuerySet method reference . html' def get_queryset(self): """ Excludes any questions that aren't published yet. Aug 26, 2019 · I'm still trying to figure out how to do the other one. filter(field=value) or shall I check for None: if value is None: filtered_queryset = queryset. filter. A boolean that specifies whether the Filter should use filter or exclude on the queryset. In this blog, we will take a closer look at QuerySets in Django and how they work. IntegerField(null=True) class MyFilter(django_filters. It is an “empty” operation that is dropped from any expression, leading to some confusion. exclude(mycolumn__total=0) So to filter out null Json fields and Json fields with a value of 0 under the total key use: Référence de l’API QuerySet ¶. exclude(alias__isnull=True) If you need to exclude null values and empty strings, the preferred way to do so is to chain together the conditions like so: Name. Something like this should work in Django 1. adkr vgrf hdpu czmpp pvhjqvu bwv qdxdx ppo ishwll viws nxnh rnq iqtyia mfdjyi iggzvg