I am having trouble with updating fields of a model instance. The model is as follows:
class commonInfo(models.Model):
mothers_id = models.IntegerField(primary_key=True)
date = models.DateField()
data_collector = models.CharField(max_length=50)
Essentially, I just want to do this, but it won't work because commonInfo has a user defined primary key
commonInfo_form(request.POST or None).is_valid()
Since I am updating, I am overriding date and data_collector, but not mothers_id. So I would want to do something like this, but this specific code is not working
obj = commonInfo.objects.get(pk=commonInfo_id)
form = commonInfo_form(request.POST)
date = form.cleaned_data['data_collector'] #this line is not working
data_collector = form.cleaned_data['data_collector'] #this line is not working
obj.update(**{'date':date, 'data_collector':data_collector})
any ideas? I feel like it is just those two lines that I need to fix. Or if there is a more pythonic way or built method in Django?
Just validate with isinstance. so like,
if isinstance(request.POST['date'], datetime.date) and isinstance(request.POST['data_collector'], str):
# you might have to use getattr for request.POST here, I'm not sure
# and request.POST['date'] would have to be converted from a string to datetime.date I think
date = request.POST['date']
data_collector = request.POST['data_collector']
obj.update(**{'date':date, 'data_collector':data_collector})
The process for adding a record from a form is different from updating an existing instance. All you need to do differently is indicate which instance to bind the form to when you create it, ex:
obj = commonInfo.objects.get(pk=commonInfo_id)
form = commonInfo_form(request.POST, instance=obj)
Related
class PurchaseOrder(models.Model):
purchase_order_id = models.AutoField(primary_key=True)
purchase_order_number = models.CharField(unique=True)
vendor = models.ForeignKey(Vendor)
i am creating Purchase Order(po) table. when po created i have to update purchase_order_number as "PO0"+purchase_order_id ex PO0123 (123 is Primary key). so i am using def save in models to accomplish this
def save(self):
if self.purchase_order_id is not None:
self.purchase_order_number = "PO"+str(self.purchase_order_id)
return super(PurchaseOrder, self).save()
It is working fine with single creation but when i try to create bulk of data using locust(Testing tool) its giving an error duplicate entry for PurchseOrdernumber Can we modify field value in models itself some thing like this
purchase_order_number = models.CharField(unique=True,default=("PO"+self.purchase_order_id )
To be honest, I don't think it should work when you create multiple instances. Because as I can see from the code:
if self.purchase_order_id is not None:
self.purchase_order_number = "PO"+str(self.purchase_order_id)
Here purchase_order_id will be None when you are creating new instance. Also, until you call super(PurchaseOrder, self).save(), it will not generate purchase_order_id, meaning purchase_order_number will be empty.
So, what I would recommend is to not store this information in DB. Its basically the same as purchase_order_id with PO in front of it. Instead you can use a property method to get the same value. Like this:
class PurchaseOrder(models.Model):
purchase_order_id = models.AutoField(primary_key=True)
# need to remove `purchase_order_number = models.CharField(unique=True)`
...
#property
def purchase_order_number(self):
return "PO{}".format(self.purchase_order_id)
So, you can also see the purchase_order_number like this:
p = PurchaseOrder.objects.first()
p.purchase_order_number
Downside of this solution is that, you can't make any query on the property field. But I don't think it would be necessary anyway, because you can do the same query for the purchase_order_id, ie PurchaseOrder.objects.filter(purchase_order_id=1).
Ok im new to django
So ive got a situation where i want a formset to have dynamic initial data
So basically here is what im looking for.
each form in the formset to have a different UserID
and a set of groups permission which they can choose from based from the initial data
here is my form
class assignGroupPermissionToUser(forms.ModelForm):
UserID = forms.ModelChoiceField(queryset=None)
Groups = forms.ModelMultipleCHoiceField(queryset=None, widget=FilteredSelectMultiple("Groups")
class Meta:
model=User
def __init__(self,*args,**kwargs):
super().__init__(*args,**kwargs)
Userid = kwargs.pop("UserID")
self.fields['UserID'].queryset =User.objects.get(UserID=Userid)
Permissions = kwargs.pop("Groups")
listofPermission = None
for each perm in permission:
listofPermission |= Permissions.objects.filter(GroupID=perm)
self.fields['Groups'].queryset = listofPermission
the data i wanna pass is built into a list like so
it is called
completeList
> completeList =[['13452',{'group1':'Admin','group2':'FrontDesk'}],['3532','group1':'Supervisors','group2':'ReadOnly;}]]
where the first value in each nested loop is the UserID, and the dictionary is the groups they can choose from.
override method in View.py
....
form = assignGroupPermissionToUser()
assignment = formset_factory(form,extra=0)
formset = [ assignment.__init__(completeList[x][0],completeList[x][1]) for x in range(len(completeList))]
then i get an error that str object has no 'is_bound' field line 58 of formset.py
im trytin to get this data to show up on each form and based on the user
it will be all different but everything i try to override it fails for initial form so here i am stuck
note that the Group attribute in the modelform has a widget which is used in the admin section to filter from multiple choices.
settings
Django= 1.8
python 3.5
i erased all this code and just did two loops like so
formset = assignments(initial=[{'UserID': listofUserID[x] } for x in range(len(completeList))])
#then
for form in formset:
form.fields['permissions'].queryset = querysetiwant
I'm currently working with django project. I had to filter the data store on the database based on the user input on form (at template) as looked below.
On form user either enter value or leave it blank. So what I have to do is first find the (valid) user input and then fire appropriate query to display data as user input in the form. So final result should be displayed on table at template.
As I'm new to django, how should I have to pass the data and fire query to represent data at multiple field. As help or link related to these type problem are expected. ( I just able to filter from the database with only one form and had no concept to solve this.)
Model of my temp project is as below.
class exReporter(models.Model):
first_name = models.CharField(max_length=30)
last_name = models.CharField(max_length=30)
email = models.EmailField()
gender = models.CharField(max_length=1)
age = models.IntegerField()
label = models.IntegerField()
There are a number of approaches you can take, but here is one solution you can use that involves chaining together the appropriate filters based on the form's posted data:
*Note: To conform to Python's naming convention, rename exReporter class to ExReporter.
# views.py
def process_ex_reporter_form(request):
if request.method == "POST":
# ExReporterForm implementation details not included.
ex_reporter_form = ExReporterForm(request.POST)
if ex_reporter_form.is_valid():
# If form field has no data, cleaned data should be None.
gender = ex_reporter_form.cleaned_data['gender']
age_start = ex_reporter_form.cleaned_data['age_start']
age_end = ex_reporter_form.cleaned_data['age_end']
aggregation_group = ex_reporter_form.cleaned_data['aggregation_group']
aggregation_id = ex_reporter_form.cleaned_data['aggregation_id']
ex_reporters = ExReporter.objects.get_ex_reporters(gender, age_start,
age_end, aggregation_group, aggregation_id)
else:
# Pass back form for correction.
pass
else:
# Pass new form to user.
pass
# models.py
class ExReporterManager(models.Manager):
def get_ex_reporters(self, gender, age_start, age_end, aggregation_group,
aggregation_id):
ex_reporters = super(ExReporterManager, self).get_query_set().all()
# Even though the filters are being applied in separate statements,
# database will only be hit once.
if ex_reporters:
if gender:
ex_reporters = ex_reporters.filter(gender=gender)
if age_start:
ex_reporters = ex_reporters.filter(age__gt=age_start)
if age_end:
ex_reporters = ex_reporters.filter(age__lt=age_end)
# Apply further filter logic for aggregation types supported.
return ex_reporters
I'm having problems trying to validate a form so that it only ever picks a distinct partner. The classes work like this:
class EmpployeeAdmin(admin.ModelAdmin):
#.......
class EmployeeRoles(models.Model):
partner = model.ForeignKey(Partner, relative_name='employee')
employee = model.ForeignKey(Employee, relative_name='partner')
class EmployeeRolesInline(admin.TabularInline):
model = EmployeeRoles
extra = 0
form = EmployeeRolesForm
Inside my forms.py I use the clean_partner function to try and validate that the current Employee only has one partner of the same name. They can have multiple EmployeeRoles objects with different partners, but they should only be assigned a partner once.
class EmployeeRolesForm(forms.ModelForm):
def clean_partner(self):
partner = self.cleaned_data.get('partner')
partner_ids=[int(p.partner_id) for p in self.instance.employee.partners.all()]
if self.instance.partner_id is not None:
return
else:
if partner.id in partner_ids:
raise forms.ValidationError("Partner already chosen")
This doesn't work, it gives me an error that self.instance.employee.partners.all() is empty. I think it has something to do with the form being unbounded and I'm not sure how to solve the problem. It's the same problem I had when I tried to filter the partner selection after every save so you only see the partners you don't have when you try to add a new employeerole. If anyone can suggest a way around the error I'd appreciate it.
You can just use unique_together in your model:
class EmployeeRoles(models.Model):
partner = model.ForeignKey(Partner, relative_name='employee')
employee = model.ForeignKey(Employee, relative_name='partner')
class Meta:
unique_together = (("partner", "employee"),)
I'm trying to write an internal API in my application without necessarily coupling it with the database.
class Product(models.Model):
name=models.CharField(max_length=4000)
price=models.IntegerField(default=-1)
currency=models.CharField(max_length=3, default='INR')
class Image(models.Model):
# NOTE -- Have changed the table name to products_images
width=models.IntegerField(default=-1)
height=models.IntegerField(default=-1)
url=models.URLField(max_length=1000, verify_exists=False)
product=models.ForeignKey(Product)
def create_product:
p=Product()
i=Image(height=100, widght=100, url='http://something/something')
p.image_set.add(i)
return p
Now, when I call create_product() Django throws up an error:
IntegrityError: products_images.product_id may not be NULL
However, if I call p.save() & i.save() before calling p.image_set.add(i) it works. Is there any way that I can add objects to a related object set without saving both to the DB first?
def create_product():
product_obj = Product.objects.create(name='Foobar')
image_obj = Image.objects.create(height=100, widght=100, url='http://something/something', product=product_obj)
return product_obj
Explanation:
Product object has to be created first and then assign it to the Image object because id and name here is required field.
I am wondering why wouldn't you not require to make a product entry in DB in first case? If there is any specific reason then i may suggest you some work around?
EDIT: Okay! i think i got you, you don't want to assign a product to an image object initially. How about creating a product field as null is equal to true.
product = models.ForeignKey(Product, null=True)
Now, your function becomes something like this:
def create_product():
image_obj = Image.objects.create(height=100, widght=100, url='http://something/something')
return image_obj
Hope it helps you?
I got same issue with #Saurabh Nanda
I am using Django 1.4.2. When I read in django, i see that
# file django/db/models/fields/related.py
def get_query_set(self):
try:
return self.instance._prefetched_objects_cache[rel_field.related_query_name()]
except (AttributeError, KeyError):
db = self._db or router.db_for_read(self.model, instance=self.instance)
return super(RelatedManager,self).get_query_set().using(db).filter(**self.core_filters)
# file django/db/models/query.py
qs = getattr(obj, attname).all()
qs._result_cache = vals
# We don't want the individual qs doing prefetch_related now, since we
# have merged this into the current work.
qs._prefetch_done = True
obj._prefetched_objects_cache[cache_name] = qs
That 's make sese, we only need to set property _prefetched_objects_cache for the object.
p = Product()
image_cached = []
for i in xrange(100):
image=Image(height=100, widght=100, url='http://something/something')
image_cached.append(image)
qs = p.images.all()
qs._result_cache = image_cached
qs._prefetch_done = True
p._prefetched_objects_cache = {'images': qs}
Your problem is that the id isn't set by django, but by the database (it's represented in the database by an auto-incremented field), so until it's saved there's no id. More about this in the documentation.
I can think of three possible solutions:
Set a different field of your Image model as the primary key (documented here).
Set a different field of your Production model as the foreign key (documented here).
Use django's database transactions API (documented here).