TypeError: Direct assignment to the forward side of a many-to-many set is prohibited. Use technicians.set() instead - django-models

I keep getting this very same type error even though I am using set. Can someone maybe point out what I'm doing wrong in my api endpoint?
views.py
#require_http_methods(["GET", "POST"])
def api_requerimientos(request):
if request.method == "GET":
requerimientos = FormularioCliente.objects.all()
return JsonResponse(
{"requerimientos": requerimientos},
encoder=FormularioClienteEncoder,
)
elif request.method == "POST":
print("POST REQUEST HIT")
try:
content = json.loads(request.body)
except json.JSONDecodeError:
return HttpResponseBadRequest("Invalid JSON in request body")
requerimiento = FormularioCliente(**content) # Create a new FormularioCliente object
if "technicians" in content and isinstance(content["technicians"], list):
try:
technicians_id_list = content["technicians"]
technicians = Technician.objects.filter(employee_number__in=technicians_id_list)
requerimiento.technicians.set(technicians)
requerimiento.save()
print('requerimiento:', requerimiento)
except Technician.DoesNotExist:
pass
requerimiento.save() # Save the object to the database
models.py
class FormularioCliente(models.Model):
empresa = models.CharField(max_length=21, null=True, unique=True)
titulo = models.CharField(max_length=66)
descripcion = models.CharField(max_length=66)
enlace = models.URLField(null=True)
tipo = models.CharField(max_length=17, choices=TIPO_REQUIRIMIENTO, default="tecnologia")
date = models.DateField(null=True, auto_now_add=True)
time = models.TimeField(null=True, auto_now_add=True)
entrega = models.DateField(null=True)
finished = models.CharField(max_length=19, choices=TIPO_FINALIZACION, default="Abierto")
technicians = models.ManyToManyField(Technician, blank=True)
special_hours = models.SmallIntegerField(default=0)
regular_hours = models.PositiveSmallIntegerField(default=1)
total_hours = models.SmallIntegerField(default=1)
importancia = models.PositiveSmallIntegerField(default=1)
file = models.FileField(upload_to='files', blank=True)
updated = models.DateField(auto_now=True)
def __str__(self):
return f'{self.titulo}: {self.descripcion} # {self.date}'
def technicians_as_json(self):
return list(self.technicians.all().values())
class Technician(models.Model):
name = models.TextField()
employee_number = models.SmallIntegerField(unique=True, primary_key=True)
def __str__(self):
return self.name + " - " + str(self.employee_number)
encoders.py
class TechnicianEncoder(ModelEncoder):
model = Technician
properties = ["name", "employee_number"]
class FormularioClienteEncoder(ModelEncoder):
model = FormularioCliente
properties = [
"id",
"empresa",
"titulo",
"descripcion",
# "user",
"enlace",
# "tipo",
# "File",
"tipo",
"date",
"time",
"entrega",
"finished",
"technicians", # <-- Add this
"special_hours",
"regular_hours",
"total_hours",
"importancia",
"updated",
]
encoders = {"technicians": TechnicianEncoder()}
I also tried to loop through technicians queryset and add it to the instance one by one as well via the add() method but that also didn't work.
I even tried this:
techs = list(requerimiento.technicians.filter(employee_number__in=technicians_id_list).all())
requerimiento.technicians.set(techs)
None of it worked

Related

Django - Query from a sub-table

I have an application that has a dropdown menu among other things.
The menu is created based on the requirements. I wrote a query that checks the statuses and calculates how many requirements are in a given status. Then he builds a menu out of it. However, I have a problem because sometimes a requisition has been created but no items have been added to it. In that case, my menu shows this as one of the items. This is not what he expects. I would like the query to return and count only those requirements in a given status that have children.
Below I paste the model code and inquiries.
class D_DemandStatus(ModelBaseClass):
status = models.CharField(max_length=20, unique=True)
name = models.CharField(max_length=50)
created_user = models.ForeignKey(User, on_delete=models.PROTECT)
def save(self, *args, **kwargs):
user = get_current_user()
if user and not user.pk:
user = None
if not self.pk:
self.created_user = user
self.modified_by = user
super(D_DemandStatus, self).save(*args, **kwargs)
def __str__(self):
return self.name
class Meta:
verbose_name = 'Demand status'
verbose_name_plural = 'Demands status'
class Demand(models.Model):
name = models.CharField(max_length=500)
status = models.ForeignKey(D_DemandStatus, default=3, on_delete=models.PROTECT, )
insert_user = models.ForeignKey(User, on_delete=models.PROTECT, editable=False)
insert_date = models.DateTimeField(default=datetime.datetime.now, editable=False)
def save(self, *args, **kwargs):
user = get_current_user()
if user and not user.pk:
user = None
if not self.pk:
self.insert_user = user
self.status = D_DemandStatus.objects.get(status='PREPARED')
self.modified_by = user
super(Demand, self).save(*args, **kwargs)
def __str__(self):
return self.name
def submitt(self, *args, **kwargs):
if self.pk :
dict_status = D_DemandStatus.objects.get(status='WAITING')
print(dict_status)
self.demanddetails_set.filter(demand_id = self.pk).update(status=dict_status)
self.status = dict_status
self.save()
def status_actualize(self, *args, **kwargs):
if self.pk :
dict_status = D_DemandStatus.objects.get(status='ORDERED')
items_status = DemandDetails.objects.filter(demand=self.pk).values('status').distinct()
if len(items_status) == 1 and items_status[0]['status'] == dict_status.id :
self.status = D_DemandStatus.objects.get(status='ORDERED')
#elif len(items_status) > 1 :
# self.status = D_DemandStatus.objects.get(status='INPROGRESS')
self.save()
class Meta:
verbose_name = 'Demand'
verbose_name_plural = 'Demands'
class DemandDetails(models.Model):
demand = models.ForeignKey(Demand, on_delete=models.CASCADE, related_name='items')
component = models.ForeignKey(Component, on_delete=models.CASCADE)
order_item = models.ForeignKey(OrderItem, null=True, on_delete=models.PROTECT, editable=False, related_name='demand_details_item')
quantity = models.IntegerField(default=1)
comment = models.CharField(max_length=150, blank=True)
status = models.ForeignKey(D_DemandStatus, default=3, on_delete=models.PROTECT, )
insert_user = models.ForeignKey(User, on_delete=models.PROTECT, editable=False)
insert_date = models.DateTimeField(auto_now_add=True)
def quantityUpdate(self, val):
if self.pk :
self.quantity = val
self.save()
def save(self, *args, **kwargs):
user = get_current_user()
if user and not user.pk:
user = None
if not self.pk:
self.insert_user = user
self.status = D_DemandStatus.objects.get(status='PREPARED')
if not self.pk:
try:
super(DemandDetails, self).save(*args, **kwargs)
except IntegrityError as e:
obj = DemandDetails.objects.get(demand_id=self.demand_id, component_id=self.component_id)
obj.quantity = obj.quantity + 1
obj.save()
else:
super(DemandDetails, self).save(*args, **kwargs)
def __str__(self):
return self.demand.name
class Meta:
verbose_name = 'Demand detail'
verbose_name_plural = 'Demand details'
constraints = [
models.UniqueConstraint(fields=['demand_id', 'component_id'], name='epm - DemandDetail (demand, component)' )
]
The query that works now looks like this:
demand_list = Demand.objects.values('status__name', 'status__id', 'status__status').annotate(count=Count('status__name')).filter(Q(status__status='WAITING') | Q(status__status='PREPARED')).order_by('-status__name')
In this case, however, even if the demand is empty (no items added), it is counted as 1
So I have changed the code a little, but it doesn't work as I would like, because it also counts the individual elements of the demand - which is obvious, because the query returns the subsequent rows that are counted.
demand_list = Demand.objects.values('status__name', 'status__id', 'status__status').annotate(count=Count('status__name'), piece=Count('demanddetails')).filter(Q(piece__gte=1)).filter(Q(status__status='WAITING') | Q(status__status='PREPARED')).order_by('-status__name')
I need to write the query in such a way that I get a list of statuses with numbers of demands only which have derived elements in DemandDetails. If a Demand exists but has no derived elements then it is not taken into account - rather it is counted as 0. This is important because in the extreme case there may be only one Demand which is empty and then I want to have information about it in the menu but with the number 0.
I hope I have managed to write clearly what I chaie.
Please help me to create a suitable query.
Regards

Update Successfully but Data not update in db. Django rest framework

I'm working on my final year project, and I need some help to understand what is actually happening, The problem is that: I hit the Update request through postman which gives the successful message for updating the data. but when I check my Database there is no updated data. I also did the debugging but there was no exception by which I can understand the problem Anyone can please help me?
I'm using
PgAdmin for my database.
Django==4.0.2
djangorestframework==3.13.1
djangorestframework-jwt==1.11.0
djangorestframework-simplejwt==5.0.0
psycopg2==2.9.3**.
My Models:
class Company(Base):
company_name = models.CharField(max_length=255, db_column='Company_Name')
company_email = models.EmailField(unique=True, max_length=255, db_column='company_email')
company_manager_name = models.CharField(max_length=255, db_column='Manager_Name')
company_address = models.CharField(max_length=255, db_column='Company_address')
about_company = models.TextField()
company_website = models.URLField(max_length=200)
is_active = models.BooleanField(default=True, db_column='IsActive', help_text='I will use this for enable/disable '
'a specific record')
class Meta:
db_table: 'Company'
def __str__(self):
return self.company_name
def save(self, *args, **kwargs):
try:
if not self.pk:
self.company_email = self.company_email.replace(" ", "").lower()
super().save()
except Exception:
raise
class Base(models.Model):
"""Following fields are abstract and will be use in All over the project Any time Anywhere"""
create_by = models.BigIntegerField(db_column='CreatedBy', null=True, blank=True, default=0)
create_on = models.DateTimeField(db_column='CreatedOn', auto_now_add=True)
modified_by = models.BigIntegerField(db_column='ModifiedBy', null=True, blank=True, default=0)
modified_on = models.DateTimeField(db_column='ModifiedOn', auto_now=True)
deleted_by = models.BigIntegerField(db_column='DeletedBy', null=True, blank=True, default=0)
deleted_on = models.DateTimeField(db_column='DeletedOn', auto_now=True)
status = models.BigIntegerField(db_column='Status', default=0, help_text='I will use this field for making'
'the status like pending approved and '
'for some other purpose by Default it is '
'Zero which has no meaning', )
class Meta:
abstract: True
serializer.py:
class CompanyUpdateSerializer(serializers.ModelSerializer):
company_name = serializers.CharField(required=True, allow_null=False, allow_blank=False)
company_email = serializers.CharField(required=True, allow_null=False, allow_blank=False)
company_manager_name = serializers.CharField(required=True, allow_null=False, allow_blank=False)
company_address = serializers.CharField(required=True, allow_null=False, allow_blank=False)
about_company = serializers.CharField(required=True, allow_null=False, allow_blank=False)
company_website = serializers.URLField(allow_blank=False, allow_null=False)
class Meta:
model = Company
fields = ['id', 'company_name', 'company_email', 'company_manager_name', 'company_address', 'about_company',
'company_website']
def update(self, instance, validated_data):
try:
instance.company_name = validated_data.get('company_name', instance.company_name)
instance.company_email = validated_data.get('company_email', instance.company_email)
instance.company_manager_name = validated_data.get('company_manager_name', instance.company_manager_name)
instance.company_address = validated_data.get('company_address', instance.company_address)
instance.about_company = validated_data.get('about_company', instance.about_company)
instance.company_website = validated_data.get('company_website', instance.company_website)
instance.save()
return instance
except Exception as e:
raise e
Views.py
def put(self, request, pk=None):
try:
id1 = pk
saved_company = Company.objects.get(pk=id1)
data = request.data
serializer = CompanyUpdateSerializer(instance=saved_company, data=data)
if serializer.is_valid():
serializer.save()
return self.send_response(success=True, code=f'200', status_code=status.HTTP_200_OK,
description='Company is updated')
return self.send_response(code=f'422', status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
description=serializer.errors)
except ObjectDoesNotExist:
return self.send_response(code='422', status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
description="No Company matches the given query.")
except IntegrityError:
return self.send_response(code=f'422', status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
description="Email Already Exist")
except Company.DoesNotExist:
return self.send_response(code=f'422', status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
description="Company Model doesn't exists")
except FieldError:
return self.send_response(code=f'500', description="Cannot resolve keyword given in 'order_by' into field")
except Exception as e:
return self.send_response(code=f'500', description=e)
The problem comes from Company.save() method.
You overrode it as
class Company(Base):
...
def save(self, *args, **kwargs):
try:
if not self.pk:
self.company_email = self.company_email.replace(" ", "").lower()
super().save()
except Exception:
raise
Notice the call of super().save() inside the self.pk is None if statement block.
This will make the actual save method to be called only when the pk is None, meaning that only when a new instance is created, not when an instance is updated.
Moving the super().save() call to be outside the if statement should handle both creating and updating.
class Company(Base):
...
def save(self, *args, **kwargs):
try:
if not self.pk:
self.company_email = self.company_email.replace(" ", "").lower()
super().save(*args, **kwargs)
except Exception:
raise

Django Post request for many to many field ValueError

I am working on a post request in which the user chooses from a list of tags and makes combinations of tags. The combination of tags should then be posted. Nothing should get changed in the Tag table.
These are the models:
models.py
class Tag(models.Model):
name = models.CharField(max_length=256)
language = models.CharField(max_length=256)
objects = models.Manager()
def __str__(self):
"""Return a human readable representation of the model instance."""
return self.name or ''
#property
def tags(self):
tags = self.tagging.values('tag')
return tags.values('tag_id', 'tag__name', 'tag__language')
class Combination(models.Model):
user = models.ForeignKey(CustomUser, on_delete=models.SET_NULL, null=True)
gameround = models.ForeignKey(Gameround, on_delete=models.CASCADE, null=True)
resource = models.ForeignKey(Resource, on_delete=models.CASCADE, null=True)
tag_id = models.ManyToManyField(Tag, null=True)
created = models.DateTimeField(editable=False)
score = models.PositiveIntegerField(default=0)
objects = models.Manager()
def __str__(self):
return str(self.tag_id) or ''
This is the serializer for Combination.
serializers.py
class CombinationSerializer(serializers.ModelSerializer):
tag_id = TagWithIdSerializer(many=True, required=False, write_only=False)
resource_id = serializers.PrimaryKeyRelatedField(queryset=Resource.objects.all(),
required=True,
source='resource',
write_only=False)
gameround_id = serializers.PrimaryKeyRelatedField(queryset=Gameround.objects.all(),
required=False,
source='gameround',
write_only=False)
user_id = serializers.PrimaryKeyRelatedField(queryset=CustomUser.objects.all(),
required=False,
source='user',
write_only=False)
class Meta:
model = Combination
depth = 1
fields = ('id', 'user_id', 'gameround_id', 'resource_id', 'tag_id', 'created', 'score')
def create(self, validated_data):
user = None
request = self.context.get("request")
if request and hasattr(request, "user"):
user = request.user
score = 0
tag_data = validated_data.pop('tag_id', None)
combination = Combination(
user=user,
gameround=validated_data.get("gameround"),
resource=validated_data.get("resource"),
created=datetime.now(),
score=score
)
combination.save()
for tag_object in tag_data[0]:
combination.tag_id.add(tag_object)
return combination
def to_representation(self, instance):
rep = super().to_representation(instance)
rep['tag_id'] = TagWithIdSerializer(instance.tag_id.all(), many=True).data
return rep
I have tried posting the following JSON object to the database:
{
"gameround_id": 2015685170,
"resource_id": 327888,
"tag_id": [{"id": 2014077506, "name": "corwn","language": "en"}]
}
I am getting a ValueError: Field 'id' expected a number but got 'name'.
How can I fix this issue?
you need to provide tag id for each tag not all tag data,
Try like this
{
"gameround_id": 2015685170,
"resource_id": 327888,
"tag_id": [2014077506,2014077507]
}

ValueError: variable needs to have a value for field "id" before this many to many relationship can be used - Django

I created a datamodel in Django, and now I created a script to auto populate the models using web-scraped values. However when I run the script I get the following error:
ValueError: variable needs to have a value for field "id" before this many to many relationship can be used
Models.py
class Books(models.Model):
title = models.CharField(max_length=100)
def __str__(self):
return self.title
class Meta:
ordering = ['-title']
class Author(models.Model):
book = models.ManyToManyField(Books)
first_name = models.CharField(max_length=150)
last_name = models.CharField(max_length=200)
def __str__(self):
return "{} {}".format(self.first_name, self.last_name)
class Meta:
ordering = ['last_name','first_name']
class Book_details(models.Model):
book = models.ForeignKey(Books,
on_delete=models.CASCADE,
null=True) # models.SET_NULL weggehaald
pages = models.CharField(max_length=250)
publ_year = models.CharField(max_length=250)
edition = models.CharField(max_length=30) # paperback, hardcover, audiobook, etc
def __str__(self):
return "{} - pages: <{}>, edition: <{}>".format(self.book.title,
self.pages,
self.edition)#
class Cover(models.Model):
book = models.OneToOneField(Books,
on_delete=models.CASCADE)
path = models.CharField(max_length=500)
def __str__(self):
return "<Cover <path={}>".format(self.id, self.path)
populate_script
def add_book(title):
b = Books.objects.get_or_create(title = title)[0]
print(b)
b.save()
return b
def populate(scraped_tuple):
fake = Faker()
for _ in range(len(scraped_tuple)):
b_title = scraped_tuple[_][0][0]
new_book = add_book(b_title)
b_author_first = scraped_tuple[_][0][1].split(" ")[0]
b_author_last = scraped_tuple[_][0][1].split(" ")[1]
b_pages = scraped_tuple[_][0][2].split(" ")[0]
b_publ_year = fake.year()
b_edition = scraped_tuple[_][0][3].split(",")[0]
b_cover = scraped_tuple[_][0][4]
new_details = Book_details.objects.get_or_create(book = new_book, pages = b_pages, publ_year = b_publ_year, edition = b_edition)[0]
new_author = Author.objects.get_or_create(book = new_book, first_name = b_author_first, last_name = b_author_last)[0]
new_cover = Cover.objects.get_or_create(book = new_book, path = b_cover)[0]
The scraped_tuple is a return value from the webscraper containing the details.
(Part of) the Traceback:
Books.models.DoesNotExist: Author matching query does not exist.
File "C:\path\to\LibraryApp\Library_WebA
pp\Library\populate.py", line 45, in populate
new_author = Author.objects.get_or_create(book = new_book, first_name = b_author_first, last_nam
e = b_author_last)[0]
Followed by:
ValueError: "<Author: Mary McCarthy>" needs to have a value for field "id" before this many-to-many relationship can be used.
So, it seems that something goes awfully wrong when trying to execute the new_author statement, because of the many-to-many field "book" in the Author model. How can I resolve this. Do I need a similar function for an Author object like I have for the Book in add_book()?
It seems the new_details statement executes just fine (title and book_details appear correctly in the database in the admin part of Django).
As mentioned in the docs, user .add() to associate the records in many to many field.
def populate(scraped_tuple):
fake = Faker()
for _ in range(len(scraped_tuple)):
b_title = scraped_tuple[_][0][0]
new_book = add_book(b_title)
b_author_first = scraped_tuple[_][0][1].split(" ")[0]
b_author_last = scraped_tuple[_][0][1].split(" ")[1]
b_pages = scraped_tuple[_][0][2].split(" ")[0]
b_publ_year = fake.year()
b_edition = scraped_tuple[_][0][3].split(",")[0]
b_cover = scraped_tuple[_][0][4]
new_details = Book_details.objects.get_or_create(book = new_book, pages = b_pages, publ_year = b_publ_year, edition = b_edition)[0]
new_author = Author.objects.get_or_create(first_name = b_author_first, last_name = b_author_last)[0]
# add many to many fields this way:
new_author.book.add(new_book)
new_cover = Cover.objects.get_or_create(book = new_book, path = b_cover)[0]

Django model inserting foreign key from same model

I am building a simple comment app in Django. The app allows replies to comments and uses the same model to store comments and replies. My issues is when I try to insert a new reply, the parentpost(FK to parent comment) inserts as NULL. When I use the admin interface to insert a reply, it properly stores the parentpost ID for the parentpost I choose. So I know the issue is not within my model but within my view.
/MODEL/
class UserPost(models.Model):
name = models.CharField(max_length=50)
slug = models.SlugField(max_length=50, unique=True,
help_text='Unique value for product page URL, created from name.', editable = False)
post = models.TextField()
is_active = models.BooleanField(default=True)
meta_keywords = models.CharField("Meta Keywords", max_length=255, blank = True, null = True,
help_text='Content for description meta tag')
meta_description = models.CharField(max_length = 255, blank = True, null = True,
help_text = 'Content for description meta tag')
created_at = models.DateTimeField(auto_now_add = True)
updated_at = models.DateTimeField(auto_now = True)
parentpost = models.ForeignKey('self', blank = True, null = True)
class Meta:
#app_label = ''
db_table = 'userposts'
ordering = ['created_at']
verbose_name_plural = 'UserPosts'
def __unicode__(self):
return self.name
#models.permalink
def get_absolute_url(self):
return ('lync_posts', (), {'posts_slug': self.slug})
def save(self):
if not self.id:
d = datetime.datetime.now()
s = d.strftime('%Y-%M-%d-%H-%M-%S-%f')
slugfield = str(self.name + s)
self.slug = slugfield
super(UserPost, self).save()
/VIEW/
def reply(request, slugIn):
parentpostIn = UserPost.objects.get(slug = slugIn)
pid = parentpostIn.id
template_name = 'reply.html'
if request.method == 'POST':
form = forms.ReplyPostForm(data = request.POST)
# create a new item
if form.is_valid(): # All validation rules pass
# Process the data in form.cleaned_data
# ...
if form.is_valid():
nameIn = form.cleaned_data['name']
postIn = form.cleaned_data['post']
newPost = UserPost(name = nameIn, post = postIn, parentpost = pid)
newPost.save()
return render_to_response(template_name, locals(), context_instance = RequestContext(request))
else:
# This the the first page load, display a blank form
form = forms.NewPostForm()
return render_to_response(template_name, locals(), context_instance=RequestContext(request))
return render_to_response(template_name, locals(), context_instance=RequestContext(request))
You are trying to set the parentpost ForeignKey by id.
You should either use:
newPost = UserPost(name = nameIn, post = postIn, parentpost = parentpostIn)
or (see Django: Set foreign key using integer?):
newPost = UserPost(name = nameIn, post = postIn)
newPost.parentpost_id = pid

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