Creating multiple model instances in DRF3
django,django-models,django-views,django-rest-framework
As of Django REST framework 3.1, it is not possible to submit multiple values using form data. This is because there is no standardized way of sending lists of data with associations, which is required for handling a ListSerializer. There are plans to implement HTML JSON forms support, which would...
Is there any way around saving models that reference each other twice?
There is no way around it, you need to save one of the objects twice anyway. This is because, at the database level, you need to save an object to get its ID. There is no way to tell a sql database "save those 2 objects and assign the ids...
Library or API for inferring country/location based on submitted string?
python,django-models,geolocation,input-sanitization
There are many, usually provided by mapping or GIS vendors. For example the Google geocoding service accepts a string and returns a ranked set of locations in a standard format: https://developers.google.com/maps/documentation/geocoding/?csw=1#Geocoding Yahoo has one too: https://developer.yahoo.com/boss/geo/#overview like I said, there are many, many. They are usually free for light usage,...
Move models between Django (1.8) apps with required ForeignKey references
python,database,django-models,schema-migration
Migrating a model between apps. The short answer is, don't do it!! But that answer rarely works in the real world of living projects and production databases. Therefore, I have created a sample GitHub repo to demonstrate this rather complicated process. I am using MySQL. (No, those aren't my real...
Record Total Value in Django
There doesn't really seem to be any good reason to pre-calculate the field here. Multiplying one existing value by another is a simple operation, and there's no benefit to be gained by calculating it on save. There would only be some benefit if the value to be calculated involved a...
Can't run django project on mac imported from ubuntu
python,django,python-3.x,django-models,virtualenv
This should have thrown an error on your Ubuntu install as well. You need to change line 3 of projectName/main/admin.py to: from .models import ContactLink, ContactPost, Personnel, \ WorkCategory, Service, Skill, Work, Customer Notice the added dot . in the from .models part. The import should be relative (assuming all...
Model friends table in Django
The approach with the ManyToMany field looks good enough. If you were to create another model to hold this manually you would need to add logic to avoid duplication (maybe other things too). Also, with the ManyToMany you end up with users that have contacts...you can for example do this:...
Send email django from any host
python,django,email,django-models
This is pure python code for sending emails using SMTP Lib from threading import Thread import requests import time import smtplib def email_sender(input_message, email_to, client): ''' function to send email ''' to = email_to gmail_user = 'email of sender account' gmail_pwd = 'password of sender account' smtpserver = smtplib.SMTP("smtp.gmail.com",587) smtpserver.ehlo()...
Django ORM: All items not in table
django,django-models,django-orm
You are filtering all events with user_id=1 and exclude everything which has events with user_id = 1 which results in an empty queryset. Try this: qs = SchedulerEvent.objects.filter(user_id=<user_id>).exclude(schedulereventreceipt__event__user_id=<user_id>) which excludes all the corresponding SchedulerEventReceipt which has the current user as the user_id...
Replacing ManyToMany-Relation with ModelChoiceField
python,django,django-models,django-forms
After fiddling around I got an working solution. Wtowers proposal is not working. Why? Read that one: http://stackoverflow.com/a/13336492/2153744 So we have to handle everything on our own. forms.py # helper class: returning full_name instead of username class UserModelChoiceField(forms.ModelChoiceField): def label_from_instance(self, obj): return obj.get_full_name() class ProjectForm(forms.ModelForm): manager = UserModelChoiceField(queryset=User.objects.all(), label='Manager', required=True)...
django multy level query in foreignkey relationship
It would be like this s = Subjects.objects.get(name="No.2") q = Question.objects.get(subject=s,ques="no.23") a = Answer.objects.get(question=q,ans2="some answer?") ...
How to apply 'IN' constraint to the fields of django models
python,django,django-models,constraints
You're referring to choices. Example from the docs: from django.db import models class Student(models.Model): FRESHMAN = 'FR' SOPHOMORE = 'SO' JUNIOR = 'JR' SENIOR = 'SR' YEAR_IN_SCHOOL_CHOICES = ( (FRESHMAN, 'Freshman'), (SOPHOMORE, 'Sophomore'), (JUNIOR, 'Junior'), (SENIOR, 'Senior'), ) year_in_school = models.CharField(max_length=2, choices=YEAR_IN_SCHOOL_CHOICES, default=FRESHMAN) ...
Django GenericIPAddress field is not validating input
python,django,validation,django-models,django-orm
https://docs.djangoproject.com/en/1.8/ref/validators/#how-validators-are-run See the form validation for more information on how validators are run in forms, and Validating objects for how they’re run in models. Note that validators will not be run automatically when you save a model, but if you are using a ModelForm, it will run your validators on...
Multiple default values specified for column “id” of the table
python,django,database,postgresql,django-models
Try explicitly specifying the id field and marking it as the primary key: class UserProfile(models.Model): id = models.BigIntegerField(primary_key = True) user = models.OneToOneField(User) avatar = models.ImageField(blank=True, upload_to=get_image_path, default='/static/image/avatar/male.png') age = models.IntegerField(default=4, validators=[MinValueValidator(3), MaxValueValidator(99)]) Django should automatically create a sequence for this field. It may be that the User foreign key...
After Django update to 1.8.2 : 'OneToOneRel' object has no attribute 'unique_for_date'
Upgrade Django Rest Framework as well as Django. Support for the Django 1.8 alpha was added in 3.0.4, and at the time of writing, the latest version is 3.1.3....
How to have 2 Models/Views/Templates on one Page in Django?
python,django,django-models,django-templates,django-views
You haven't said what you have tried to do to solve this, why you think it's "way overly complicated", or why it's causing you frustration. The thing to understand is that a view is entirely responsible for a page, ie the view creates the entire response when a URL is...
Django 1.8 conditional annotation results in INNER JOIN instead of LEFT OUTER JOIN
django,django-models,django-queryset,django-orm,django-1.8
This way seems to work correctly: bars = Bar.objects .prefetch_related('foo_bar') .annotate(sum_foo=Sum( Case( When(Q(foo_bar__is_deleted=False) | Q(foo_bar__is_deleted=None), then='foo_bar__amount'), default=Value(0), output_field=IntegerField() ) ), ) ...
Django: set number of ForeignKey relations by integer value in another model
django,django-models,one-to-many
I'm not really clear on how you assign messages to tasks. However, if you need the ability to have multiple elements on each side of a relationship, you should use a ManyToManyField, not a ForeignKey. Depending on what you are actually doing, you should be able to validate the correct...
Migrate new model fields
django,postgresql,django-models,database-migration
No fields at all are being migrated when you run manage.py makemigrations <app>, as that command only creates a new migration in your <app>/migrations/ directory. It's only when you run manage.py migrate that changes are written to the database. If you are not getting the expected results, have a look...
Django Rest Framework - Non Field Error Custom Message
python,django,django-models,django-rest-framework
When you have unique_together set on a model, the serializer will automatically generate a UniqueTogetherValidator that is used to check their uniqueness. You can confirm this by looking at the output of the serializer, and introspecting what Django REST framework automatically generates: print(repr(DeviceContractSerializer())) You can then alter the validators that...
Django migrations detect the same change many times
django,django-models,django-migrations
The problem is that you are calling datetime.now() in the default parameter of the definition. That means that the default changes each time you start Django, so the system thinks you need a new migration. You should wrap that calculation into a lambda function, which will be called as necessary:...
Properly use 'next' paramater in URL, Django
python,django,python-2.7,redirect,django-models
Inside your login view, just do this: def login(request): """ Check for login and store the result in login_successful """ path = request.GET.get("next") if login_successful: if path: return HttpResponseRedirect(path) else: return HttpResponseRedirect(your_earlier_path) ...
Django-cms/Django SingleRelatedObjectDescriptor instead of object itself
django,django-models,django-cms
In your plugin you should access object fields via the instance argument to render, not self.model. Like this: from cms.plugin_base import CMSPluginBase from cms.plugin_pool import plugin_pool from cms.models.pluginmodel import CMSPlugin from django.utils.translation import ugettext_lazy as _ from links_plugin.models import Section, SectionConfig class LinksPlugin(CMSPluginBase): name = _("Links Tree Plugin") model =...
django: default for non-nullable field
I usually set to 1. In this case already existed records will be assigned to the first user. If you want you can later reassign these records in the next data migration....
Posting data from a form into the database using Django
django,django-models,django-forms
Lot's of Changes needed to your code. I'm posting a working version so that you can try. Put profile.html file as bkmks/templates/bkmks/profile.html Get it working. Customize later. profile.html <form id="taskitem_form" method="post" action=""> {% csrf_token %} {{form}} <input type="submit" name="submit" value="Add Task" class ="btn btn-primary" /> </form> model as it is....
Django date query from newest to oldest
ordered_tasks = TaskItem.objects.order_by('-created_date') The order_by() method is used to order a queryset. It takes one argument, the attribute by which the queryset will be ordered. Prefixing this key with a - sorts in reverse order....
How to read csv data into django models?
python,django,csv,django-models
This line seem to work for me: with open(TICKERS, encoding='utf-8', errors='ignore') as f: ...
Django: Store multiple & dynamically ordered model sequence
You could have a model VideoComponent with a position field as well as foreign keys to VideoClipModel and ImageModel. Then a Video model would have a many to many field to VideoComponent. class Video(models.Model): components = models.ManyToManyField('VideoComponent') class VideoComponent(models.Model): image = models.ForeignKey('ImageModel') video_clip = models.ForeignKey('VideoClipModel ') position = models.IntegerField() class...
Django 1.8: How use Model from different application?
python,django,django-models,django-1.8
You can implement the common models in common_application's models.py file as an abstract model, by adding the following to the model's class: class Meta: abstract = True Then, in other applications you can import your common models like so: from common_application.models import Model_1, Model_2, Model_3 And then instantiate model classes...
Is there a way to see the raw SQL executed by a bulk_create on django?
python,django,postgresql,django-models,django-1.8
When in debug-mode you could use the django.db.backends logger. https://docs.djangoproject.com/en/1.8/topics/logging/#django-db-backends In production I would use loggers for PostGres itself, because saving these queries from within a Django process will (probably) have major impact on your performance....
updating a model attribute in django using form
You say that "each project can assign multiple contractors" but that not how your model works - it allows a single contractor per project: class Project(models.Model): contractor=models.ForeignKey(Contractor, null=True) ForeignKey if for one to many relationships - here a Project has zero or one Contractor and a Contractor has zero, one...
Search a Many to Many Relationship
django,django-models,many-to-many,manytomanyfield
I think you just need this: # assuming you have a contributor Registration.objects.filter(contributor=your_contributor_object) ...
Callable not defined for django.db.models field default
python,django,python-3.x,django-models
You shouldn't use this method to set your default value, rather than override the save method of the model and use it there. For example: class User(models.Model): first_name = models.CharField(max_length=256) last_name = models.CharField(max_length=256) slug = models.SlugField(max_length=256, unique=True, default=uuid.uuid1) def make_slug(self): return self.first_name + self.last_name[0] def save(self, *args, **kwargs): self.slug =...
Django Model field calculated from other fields
python,django,django-models,django-admin
Figured it out (w the help of AbhiP!) Python int typecasting was the main culprit. Stupid problem to have! Below is what worked, and allowed me to not save the calculated field (but display it and make it act like a field in the model): @property def yield_num(self): if self.starts...
django-tables2: use request user in render method
django,django-models,django-tables2
Well you can use this plugin here: https://github.com/Alir3z4/django-crequest Use it like this: def render_eventResponse(self, record): from crequest.middleware import CrequestMiddleware current_request = CrequestMiddleware.get_request() user = current_request.user responseObject=record.getResponseFromUser(user) if not responseObject: return '' else: return responseObject.getResponseText ...
Get element of table by instance of foreign key.
Just to clarify a thing, using get() in this situation isn't right, quoting get() docs : If you know there is only one object that matches your query, you can use the get() method on a Manager which returns the object directly Alternatively with what Wtower mentioned,you can also use:...
Django Rest Framework PUT request on unique model field
django,django-models,django-rest-framework,django-serializer
As per the comments implementing the put method closer to the reference implementation in the docs should fix the issue. def put(self, request, pk, format=None): device = self.get_object(pk) serializer = DeviceSerializer(device, data=request.data) if serializer.is_valid(): serializer.save() return Response(serializer.data) return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST) Saving instances has a bit more information on creating, updating...
In Django template how to separate Date and time from DateTimeField?
django,django-models,django-templates
{{ object.pub_date|date:"D d M Y" }} {{ object.pub_date|time:"H:i" }} all options explained: documentation...
Django models: managing transactions when commit_manually is deprecated
python,django,django-models,override
The same logic would look like this: from django.db import models from django.db import transaction class MyModel(models.Model): # model definition def save(self, *args, **kwargs): transaction.set_autocommit(False) try: super(MyModel, self).save(*args, **kwargs) foo() # do_other_things except: transaction.rollback() raise else: transaction.commit() finally: transaction.set_autocommit(True) However, this would be equivalent to using the atomic() decorator: from...
create_user() takes at least 3 arguments (2 given) Django Social Auth use Costom User Model
django,django-models,django-admin,django-authentication,django-custom-user
Try doing this might help def create_user(self,email, password=None,**kwargs): OR check these links might help you what you want. link1 link2...
How to deal with optional GET argument?
python,django,django-models,django-views
pk = request.GET.get('pk') does not raise an exception. It gives you None instead, if pk isn't in GET. So your first case never executes. Try with: @ajax @login_required def search_dist(request): pk = request.GET.get('pk', None) if pk is None: dist_list = request.user.distributors.all() starts_with = request.GET.get('query') if starts_with: dist_list = request.user.distributors.filter( surname__istartswith=starts_with)...
Django Sorting a List inside a model
python,django,sorting,django-models
You can set the ordering and many other options for a model through the use of the meta class. So for your example: class Address(models.Model): address = models.CharField(max_length=20) ... class Meta: ordering = ['address'] This will order Address models in your queryset after they have been queried from the database....
Django's DateTimeField's “auto_now” doesn't seem to work
Because you're using update, which does the update directly in the database, whereas auto_now is done in Python. This would work: for commment in Comment.objects.filter(...): comment.text="some new text" comment.save() Obviously, this is less efficient than doing it in one go in the db. If you really need that, then you'd...
Import one model inside urls.py from other app
clients is an installed app, so you should be able to change that line to: from clients.models import Client ...
Django does not render my forms' fields
django,django-models,django-forms,django-templates,django-views
Your form inherits from forms.Form, which does not know anything about models and ignores the Meta class. You should inherit from forms.ModelForm.
DjangoRestFramework ModelSerializer: field-level validation is not working
django,django-models,error-handling,django-rest-framework,django-serializer
Field-level validation is called before serializer-level validation. So model User having username as unique=True, the field-level validation will raise exception because of username being already present. DRF's UniqueValidator does this work of raising exception when a field is not unique. As per DRF source code, class UniqueValidator: """ Validator that...
Cannot create super user use custom user model in django 1.8
python,django,django-models,django-admin,django-custom-user
REQUIRED_FIELD = ['username'] Should change to: REQUIRED_FIELDS = ['username'] ...
AttributeError when establishing a foreign key using the to_field option
From docs: The field on the related object that the relation is to. By default, Django uses the primary key of the related object. As we know PK is unique. Try setting order_number as unique in WorldEaseConsignee model: class WorldEaseConsignee(models.Model): order_number = models.IntegerField( null=False, blank=False, unique=True ) Also, set to_field...
customising a model field for serialization
django-models,django-rest-framework
First you can split the education field value by using split. Then you can serialize it accordingly. class CustomModel: def __init__(self, year,course,college,description): self.year = year self.course = course self.description = description self.college = college class CustomSerializer(NonNullSerializer): year = serializers.IntegerField() course = serializers.CharField() description = serializers.CharField() college = serializers.CharField() Add this...
Best way to sign-up django project
django,django-models,django-views
The best way is to first try the example in the documentation. If you do not have the patience to read through the documentation, here is an example of something you can try....
Divide option in django model query
python,django,django-models,django-views
You could use a method like this: class DailyObj(models.Model): ... def total_crores(self): return self.Total_Rec / 10000000 It won't be stored in the database, but will be accessible in the template with something like this: {{ daily_obj.total_crores }} Or, in keeping with your query, something like this (assuming that top10records gets...
Django Generic Foreign Key invalid literal for int() with base 10
here it says the Generic Foreign Key can be a char: ...For example, if you want to allow generic relations to models with either IntegerField or CharField primary key fields, you can use CharField for the “object_id” field on your model since integers can be coerced to strings by get_db_prep_value()......
Pinax teams - given a user find all the teams for which the user is a member
There's no need for anything so complex or inefficient. You can follow the relationships in a single query: teams = Team.objects.filter(memberships__user=user) ...
How to count users in JOINed models?
python,django,join,django-models,django-queryset
from datetime import date def add_years(d, years): try: return d.replace(year = d.year + years) except ValueError: return d + (date(d.year + years, 1, 1) - date(d.year, 1, 1)) today = datetime.date.today() ago18 = add_years(today, -18) ago25 = add_years(today, -25) # < 18 User.objects.filter(profile__birthdate__gt=ago18) # 18 <= and < 25 User.objects.filter(profile__birthdate__lte=ago18,...
InlineModelAdmin not showing up on admin page
django,django-models,django-admin
This is what you should have in admins.py: from django.contrib import admin from models import Author, Book class BookInline(admin.StackedInline): model = Book class AuthorAdmin(admin.ModelAdmin): inlines = [ BookInline ] admin.site.register(Author, AuthorAdmin) admin.site.register(Book) You probably forgot to include 'AuthorAdmin' in this line: admin.site.register(Author, AuthorAdmin) ...
Dynamically creating the related_name from META class
I think it might be sufficient to handle this like it is documented here. # myapp/models.py class User(models.Model): user = models.ForeignKey( USER, related_name="%(app_label)s_%(class)s_related" ) class Meta: abstract = True class TestModel(User): title = models.CharField(max_length=80) This way the related name would dynamically become myapp_testmodel_related. Of course you can tweak the name...
How to save the value of a jQuery sliderbar into a Person model?
jquery,django,django-models,django-forms,django-views
I eventually found a way of solving this. The overarching problem was that I was trying to add information to my Person Model which was not 'generated/originated' from my forms.py / models.py in the traditional way but rather was being 'generated' on the page from my jQuery script. I knew...
Django admin with inlines, 1 model with 2 foreigns keys to 2 different models
django,django-models,foreign-keys,django-admin
Update The code I posted earlier was wrong! I didn't read your models too carefully. Sorry about that. If you want to create CharacterSeries and CharacterUniverse while you create/edit the Character, you could do this: from django.contrib import admin from .models import Character, CharacterUniverse, CharacterSeries # No need to define...
Django 1.8 model form fields not showing when rendering template
python,html,django,django-models,django-forms
You're not passing the form to the template if the request is a GET. There's really no need to distinguish between the GET and POST in this case when creating the form instance. You can simply instantiate your form as such: form = BlockForm(request.POST or None) and drop the instantiation...
Changing Primary Key in Oracle
oracle,django-models,oracle-sqldeveloper
The biggest problem you have is all the application code which references VENDOR_NAME in the dependent tables. Not just using it to join to the parent table, but also relying on it to display the name without joining to VENDOR. So, although having a natural key as a foreign key...
Assign JSON field to model variable in django
django,django-models,django-rest-framework
If you are using djangorestframework you will need to override to_representation function in your serializer http://www.django-rest-framework.org/api-guide/serializers/#overriding-serialization-and-deserialization-behavior should be something like this def to_representation(self, obj) serialized_data = super(SerializerClassName, self).to_representation(obj) serialized_data["2or4"] = serialized_data["twoOrFour"] //Remove the old field name del serialized_data["twoOrFour"] return serialized_data This code should work where...
Return error message to custom form in Django
python,django,forms,django-models,django-forms
Answering my own question. I am a newbie and hence took a lot of time and effort to figure this our. I was simply missing this in my views: if form.is_valid(): #do something, add user ot DB return render(request, 'mudramantri/index.html', {'registered': True}) else: return render(request, 'mudramantri/index.html', {'form': form}) Since, I...
Callable in model field not called upon adding new object through Django admin
django,django-models,django-admin
Try: when_first_upload = models.DateTimeField(default=datetime.datetime.now) You need the callable itself, not the result returned by it....
django - What are the alternatives to having a ForeignKey to an abstract class?
The reason the ForeignKey cannot reference an abstract model directly is that individual models that inherit from the abstract model actually have their own tables in the database. Foreign keys are simply integers referencing the id from the related table, so ambiguity would be created if a foreign key was...
Saving a model containing a FileField in Django
Since you're using ModelForm, why not let Django handle saving the whole model? from django.shortcuts import redirect form = AudioFileForm(request.POST) if form.is_valid(): form.cleaned_data['uploader'] = request.user //view requires login form.save() return redirect(success_url) If you're using Django >=1.7, upload_to field is no longer required. However, I consider it a good practice. https://docs.djangoproject.com/en/1.8/ref/models/fields/#django.db.models.FileField.upload_to...
Django form data not submitting/visable in mysql database
django,django-models,django-forms
Submitting data to a model form does not cause it to be saved automatically. If you want save data from a model form to the database, you need to call its save() method. You could do this in the wizard's done() method. def done(self, form_list, **kwargs): # I don't know...
How to translate this raw query to Django ORM
sql,django,django-models,django-templates
Candidate.objects.filter( Q(Q(languagelevel__language__id__in=(1, 2, 3)) & Q(languagelevel__language__level__gte=1)) | Q(Q(languagelevel__language__id__in=(4, 5)) & Q(languagelevel__language__level__gte=3)) | Q(Q(languagelevel__language__id=6) & Q(languagelevel__language__level__gte=2)) )).values('id').annotate(total=Count('id')) values will only return the id of each candidate with a calculated total as total. If you want to get all of the fields (not only id), you can remove .values('id') as: Candidate.objects.filter(...
django - migrations issue after renaming app
If you don't care about your migrations, and the data, just delete the content of the migrations folder and create them again: rm -f yourapp/migrations/* touch yourapp/migrations/__init__.py ./manage.py makemigrations ...
How to get simple ForeignKey model working? (a list of class in another class)
django,django-models,django-queryset
You should reverse the foreign key relationship: class HeartRate(models.Model): timestamp = models.DateTimeField('Date and time recorded') heartrate = models.PositiveIntegerField(default=0) exercise = models.ForeignKey(Exercise, related_name='heartrates') class Exercise(models.Model): start_timestamp = models.DateTimeField('Starting time') finishing_timestamp = models.DateTimeField('Finishing time') To get all of the heartrates of an exercise: heartrates = my_exercise.heartrates.all() ...
Error on raising ValidationError as dictionary
python,django,python-2.7,django-models,django-forms
Use raise ValidationError instead of raise ValueError: def clean(self): email = self.cleaned_data["email"] try: User._default_manager.get(email=email) except User.DoesNotExist: return self.cleaned_data raise ValidationError({'email':'Email already registered. Login to continue or use another email.'}) ...
Update queryset attribute value without losing order on that attribute
Hope the following helps: for i, record in enumerate(qs): record.value = i ...
Django custom form not rendering
python,html,django,forms,django-models
The problem has to do with the src root on pycharm and the lack of import in the file views.py and urls.py.
Django OneToOneField or ForeignKey?
You are interested in the unique_together model meta option: Sets of field names that, taken together, must be unique. class Comment(models.Model): news = models.ForeignKey(Post) user = models.ForeignKey(User) # ... class Meta: unique_together = ('news', 'user') Your user field can then be simply a ForeignKey....
Modify db object field from .py file in django
Your get_model_b_by_currency is returning a queryset rather than a single instance. Every time you slice a queryset, you get a new instance. Instead, either return an instance from get_model_b_by_currency - for instance by using get() instead of filter() - or slice it once, allocate it to a variable, and modify...
Continuously add new entries to Django model
If I understands right, class MyList(models.Model): user = ForeignKey(User) list_name = CharField(...) .... def list_items(self): return self.mylistitems_set.all() class MyListItem(models.Model): mylist = ForeignKey(MyList) item_name = ..... .... A user may create as many lists an he/she wants and may add any number of items to a specific list. So logic is...
Django filter a many-to-many list of IDs
It should be categories__id__in (double underscore). See Django documentation: QuerySet API reference. UPDATE: If with a comma separated list of ids you mean a comma separated string of ids, then you should: cat_ids = self.request.QUERY_PARAMS.get('cat_ids', None).split(',') ...
How to reactivate user django
python,django,django-models,django-admin
There's nowhere to save is_active to, since you haven't assigned a database field to it. You should change the is_active in your model to: is_active = models.BooleanField(default=False) ...
F() Expression strange behavior with Django
python,django,django-models,django-templates,django-template-filters
random.choice does not guarantee to produce non-repeating items. import random random_camps = random.sample(current_campaigns, amount) is the way to go here. Update If you're worried about the speed, this question addresses quick random row selection in postgres....
Django- Staying DRY with multiple model methods
Why not just do: class MyModel(models.Model): a = models.IntegerField(default=0) b = models.IntegerField(default=0) c = models.IntegerField(default=0) @property def x(self): return self.a + self.b @property def y(self): return self.x + self.c @property def z(self): return self.x + self.y ...
Django reverse relationship name gives invalid keyword argument error
The reverse relation can be used to query related items, but you can't use it to set the object as you are trying. You need to create the params, then update the related object. params = Params.objects.create(name="Test") object_cat.params = params object_cat.save() ...
django: ForeignKeyField limit_choices_to “parents pk”?
ForeignKey field is translated into ModelChoiceField inside a Django ModelForm. If you inspect that class you will notice that this type of field has an queryset attribute required. By default Django provides the full set of objects. You can override this inside your form __init__ method by providing the parent...
Database first Django models
python,django,django-models,django-rest-framework,django-serializer
You can use the information on this link. python manage.py inspectdb > models.py https://docs.djangoproject.com/en/1.7/howto/legacy-databases/ It depends on your database, but I've worked with it and is good....
How can I avoid recursion during saving of django model
I would solve it with an additional argument to save, as opposed to attaching to pre_save: import django.db.models class Entry(models.Model): color=models.CharField(max_length="50") def save(self,create_children=True,**kwargs): if create_children and not self.pk: result = super(Entry,self).save(**kwargs) Entry(color=self.color).save(create_children=False) Entry(color=self.color).save(create_children=False) else: result = super(Entry,self).save(**kwargs) return result You want to make sure you call super(Entry,self).save(**kwargs) before you...
Form not showing in html - django
python,django,django-models,django-forms,modelform
Try using: return render(request, 'prueba.html', ctx) instead of return render_to_response('prueba.html',ctx,context_instance=RequestContext(request)) Also, don't foreget to import render as follows: from django.shortcuts import render ...
How to reverse query objects for multiple levels in django?
You start with the model whose objects you want to get, Level4, then follow the relationships with the double-underscore syntax. Level4.objects.filter(level3__level2__level1=my_level1_object) ...
How to filter objects for count annotation in Django?
python,django,django-models,django-aggregation
Just discovered that Django 1.8 has new conditional expressions feature, so now we can do like this: events = Event.objects.all().annotate(paid_participants=models.Sum( models.Case( models.When(participant__is_paid=True, then=1), default=0, output_field=models.IntegerField() ))) ...
Using .update with nested Serializer to post Image
django,rest,django-models,django-rest-framework,imagefield
As noted in the docs, .update() doesn't call the model .save() or fire the post_save/pre_save signals for each matched model. It almost directly translates into a SQL UPDATE statement. https://docs.djangoproject.com/en/1.8/ref/models/querysets/#update Finally, realize that update() does an update at the SQL level and, thus, does not call any save() methods on...
Django column “name” of relation “django_content_type” does not exist
Encountered this when upgrading to 1.8 and migrating from MySQL to Postgres. I can't explain why the error occurs, but I was able to get around it by manually adding the column: Delete all migrations Delete records from django_migrations Manually add name column: ALTER TABLE django_content_type ADD COLUMN name character...
When should I be using null=False on django model fields
NOT NULL is a tool to enforce data integrity if that column must never be empty, which is always a good thing. It's better to error out hard and early, than to discover later on that something went wrong and you're left with inconsistent or missing data. Data integrity is...
Please help me decipher a traceback for “ValueError: invalid literal for int()” in my models
django,django-models,django-middleware
You are trying to match a foreign key to a string, you need to provide the model ProductPart.objects.values().filter(part=v) Note: the values isn't necessary either ProductPart.objects.filter(part=v) From the documentation for Values a QuerySet subclass that returns dictionaries when used as an iterable, rather than model-instance objects. In other words, you are...
Inheritance in Django: child class updates parent with empty fields
python,django,python-3.x,inheritance,django-models
I suspect the problem is that you are inheriting from auth_models.User. This is multi-table inheritance and isn't really appropriate for this situation. See the django docs here: https://docs.djangoproject.com/en/1.8/topics/auth/customizing/#extending-django-s-default-user Which basically say if you want to store profile data in a separate table there is no need to extend auth_models.User. Just...
Django Prefix the PK ID field of a Model
In don't understand what you mean by "Prefix the PK ID field with j1_, followed by a unique ID in base 36"... But anyway: of course you can use whatever field type (including your own custem field type) you want as primary key - you just have to specify it...
How to filter by field of field (multi level relationship) in django admin?
python,django,django-models,django-admin
Easy school_name = "your school name" Students_in_school = Student.objects.filter(grade__school__name = school_name) Sorry I wrote this on Bus...
Django admin filters on remote field via get_list_filter
django,django-models,django-admin
I don't have enough reputation to add a comment, so I'll write here, even if this is not a real answer. It looks there's an open ticket on this topic: lookup_allowed fails to consider dynamic list_filter You can use two different workarounds to quickly solve this problem until it will...
Setting unique=True on a ForeignKey has the same effect as using a OneToOneField
python,django,python-3.x,django-models,django-1.8
primary_key implies unique=True. So, as the warning says, you should probably be using a OneToOneField.