I have 2 models employee and leave, where Employee is the foreign key in Leave. I want to display the leave requests by a specific employee on a page when they log in.
i'm not able to get the leave data populated on, and if there are more than 2 leaves applied by a single employee i get an error saying 2 items found
here is my code
models.py
class Employee(models.Model):
user=models.OneToOneField(User, on_delete=models.CASCADE)
no_of_leaves=models.IntegerField(
null=False,
validators=[
MinValueValidator(1),
MaxValueValidator(24)
],
default=24
)
def __str__(self):
return self.user.username
class Leave(models.Model):
employee=models.ForeignKey(Employee,on_delete=models.CASCADE,default="")
start_date=models.DateField(auto_now_add=False)
end_date=models.DateField(auto_now_add=False)
req_date=models.DateTimeField(default=datetime.datetime.now())
STATUS_OPTIONS = (
("Approve","Approve"),
("Pending","Pending"),
("Decline","Decline"),
)
approved=models.CharField(max_length=10,choices=STATUS_OPTIONS,default='Pending')
def __str__(self):
return self.employee.user.username
#property
def date_diff(self):
return (self.start_date - self.end_date).days
views.py
def home(request):
user = request.user
u = User.objects.get(username=user)
e = Employee.objects.get(user=user.id)
leave = Leave.objects.get_or_create(employee=e)
print(leave)
nofleaves=None
if user.is_superuser:
pass
else:
nofleaves=u.employee.no_of_leaves
context={'nofleaves':nofleaves,'leave':leave,}
return render(request,"leaveApp/home.html",context)
Just like #Jao said get is to fetch only one data while there is a many to one relationship between Leave and Employee that means there can be multiple Leave for one employee thus get will throw an error.
You should use filter:
Change this line
leave = Leave.objects.get_or_create(employee=e) to something like
leave = Leave.objects.filter(employee=e.id)
if not leave.exists():
leave = Leave.objects.create(employee=e)
This other question might help.
The thing is you should use get for only one data. You shouldn't use get on a many-to-one relathionship. The logic is, there can be multiple Leave by Employee so you can't have a consistent use of get.
What you can use is filter but I'd use related names/related fields which will allow you to use employee.leaves if you define it correctly.
Related
I am trying to make a warehouse management system with Django 3.2 based on this models:
class itemtype(models.Model):
item_id = models.IntegerField(primary_key=True)
item_name = models.CharField(max_length=100)
group_name = models.CharField(max_length=100)
category_name = models.CharField(max_length=100)
mass = models.FloatField()
volume = models.FloatField()
used_in_storage = models.BooleanField(default=False, null=True)
class Meta:
indexes = [
models.Index(fields=['item_id'])
]
def __str__(self):
return '{}, {}'.format(self.item_id, self.item_name)
class material_storage(models.Model):
storage_id = models.AutoField(primary_key=True)
material = models.ForeignKey(itemtype, on_delete=models.PROTECT)
amount_total = models.IntegerField(null=True)
price_avg = models.FloatField(null=True)
order_amount = models.IntegerField(null=True)
order_price = models.IntegerField(null=True)
timestamp = models.DateTimeField(default=timezone.now)
def __str__(self):
return '{}, {} avg.: {} ISK'.format(self.material, self.amount, self.price)
"itemtype" defines basically the possible objects which could be stored and "material_storage" shows what is in stock. I tried to combine the total amount of every item as well as the average price paid for it and the amount and price for a single order in the same database row. The idea is to get the last record for the chosen item/material when a new order happens, add the amount of that order and recalculate the avg price.
Theoretically this could be split up on two tables, but I don't see a reason to do so at the moment.
However, I am not able to figure out the actual function code to do the calculations. I am new to Django and therefor a bit overwhelmed by the complexity. I tried to use class based views and model forms, for the easy stuff that worked fine but now I am kind of lost.
Making a form just for adding new rows to that storage table was ok.
class NewAssetForm(forms.ModelForm):
material = MaterialChoiceField(models.itemtype.objects.filter(used_in_storage= True))
def __init__(self, *args, **kwargs):
super(NewAssetForm, self).__init__(*args, **kwargs)
self.fields['amount'].widget.attrs['min'] = 1
self.fields['price'].widget.attrs['min'] = 1
class Meta:
model = models.material_storage
fields = (
'material',
'amount',
'price'
)
widgets = {
'material': forms.Select(),
}
Same for the View to process it.
class NewItemView(FormView):
template_name = 'assetmanager/newasset.html'
form_class = forms.NewAssetForm
success_url = '/storage/current'
def form_valid(self, form):
return super().form_valid(form)
But now I am stuck. I thought this should be a fairly standard task, but I couldn't find a solution for it by now. The Idea was to put it in the form_valid function, take the material from the form to find the latest relevant record, add the new amount as well as calculate the new average price and save all together to the model. So far i only found a few examples comparable with my problem at all and I wasn't able to translate them to my setup, so maybe someone can give me a hint for a more successful search or provide me an example how to approach this topic.
thx in advance.
To modify the values of the form fields, you can override "clean" method and provide values to the form fields. Data can be accessed using "self.cleaned_data", it is a dictionary.
class NewAssetForm(ModelForm):
def clean(self):
super().clean()
# place code that retrieves existing data and calculate new values.
self.cleaned_data['price'] = 'New Value'
cleaned_data will be passed to "form_valid", there you can call the save function. "form.save()" will create a new row, make sure you are passing valid values to the views. Since you are accepting few fields in the form, make sure you have default values for the fields that are not included in the form object.
Thank you for your answer I found a solution by using the form_valid() method within the FormView. The majority of the code is used to create entries based on the existing entries or to check whether there are already entries for the same material.
class NewItemView(FormView):
template_name = 'assetmanager/newasset.html'
form_class = forms.NewAssetForm
success_url = '/storage/current'
def form_valid(self, form):
try:
# check if there is already a record for this material.
material_storage.objects.filter(material_id = form.cleaned_data['material'])[:1]
# getting total amount and average price values from latest entry with said material.
total_amount = material_storage.objects.values('amount_total').filter(material_id=form.cleaned_data['material']).order_by('-timestamp')[:1][0]['amount_total']
avg_price = material_storage.objects.values('price_avg').filter(material_id=form.cleaned_data['material']).order_by('-timestamp')[:1][0]['price_avg']
amount = form.cleaned_data['amount']
price = form.cleaned_data['price']
# calculating new total amount and average price based on old values and new entry.
form.instance.amount_total = total_amount + amount
form.instance.price_avg = ((avg_price * total_amount) + (price * amount)) / (total_amount + amount)
form.save()
except material_storage.DoesNotExist:
# if there is no entry for the chosen material yet, amount = total amount, price = average price.
form.instance.amount_total = form.cleaned_data['amount']
form.instance.price_avg = form.cleaned_data['price']
form.save()
return super().form_valid(form)
For now this solves my problem, however I don't know if the chosen location (form_valid()) makes sense - your answer suggests it would make more sense elsewhere.
Also, checking if an entry already exists for the material and selecting values from such an entry are pretty sure not very elegant and efficient. But as already mentioned, I am a beginner - I would be happy about any suggestions for improvement.
I am also not sure yet if this handles every probable special case which could appear...
Hi all!
New in Django, and confused, help is appreciated! I've created a table, , thanks to a stackoverflow users, like:
Organization
Total amount of appeals
Amount of written form appeals
Amount of oral form appeals
Organization 1
3
1
2
Organization 2
2
1
1
Have three models:
class Organization(models.Model):
organization_name = models.CharField(max_length=50)
class AppealForm(models.Model):
form_name = models.CharField(max_length=50)
class Appeal(models.Model):
organization = models.ForeignKey(Organization, on_delete=models.CASCADE)
appeal_form = models.ForeignKey(AppealForm, on_delete=models.CASCADE)
applicant_name = models.CharField(max_length=150)
appeal_date = models.DateField()
Objects of Organization model:
organization_name
Organization 1
Organization 2
Objects of AppealForm model:
form_name
In written form
In oral form
Objects of Appeal model:
organization
appeal_form
applicant_name
Organization 1
In written form
First and Last name
Organization 1
In oral form
First and Last name
Organization 1
In oral form
First and Last name
Organization 2
In written form
First and Last name
Organization 2
In oral form
First and Last name
In the function of views.py file, I've created a query to render, like:
from django.db.models import Count, Q
organizations = Organization.objects.annotate(
).annotate(
total=Count('appeal'),
total_written=Count('appeal', filter=Q(appeal__appeal_form__form_name='in written form')),
total_oral=Count('appeal', filter=Q('appeal__appeal_form__form_name='in oral form'))
)
And now I want to filter table contents by AppealForm model and date of appeals (appeal_date field of Appeal model). Case: User opens a table and from search bar above the table chooses which appeal form and/or the range of dates to see.
Question: How to filter the query which is above in views.py using django-filter package?
The most general way to define a complicated filter is to use the method argument. I can't say I completely understand your problem, but you can apply any filter for which you can dream up a queryset in this way. In outline:
import django-filters as DF
class SomeFilters( DF.FilterSet):
name = DF.xxxFilter( method='my_method', field_name='object_field', label='whatever', ...)
...
def my_method( self, qs, name, value):
# in here you create a new more restrictive queryset based on qs
# to implement your filter, and return it.
# name is the field name. Note, you don't have to use or follow it
# value is the value that the user typed
qs = qs.filter( ...) # or .exclude, or complicated stuff
return qs
Here's a fairly simple method that I wrote to create an annotation with the value of a field stripped of spaces, and then to do a text-contains filter on that.
def filter_array_desc( self, qs, name, value):
value = value.replace(' ','')
qs = qs.annotate(
arr_d_nospaces = Replace( 'array_desc', Value(' '), Value('')) # delete all spaces
).filter(
arr_d_nospaces__icontains = value )
return qs
Here's a general one that can be applied to any field through a ChoiceFilter to filter whether the field is blank or not:
YESNO = (('Y','Yes'), ('N','No'))
marr_b = FD.ChoiceFilter( field_name='marr', label='M_array is blank', method='filter_blank_yesno',
choices=YESNO, empty_label="Don't Care" )
...
def filter_blank_yesno( self, qs, name, value):
if value=="Y":
return qs.filter(**{ name:'' })
elif value=="N":
return qs.exclude( **{ name:'' })
raise ValueError(f'filter_blank_yesno received value="{value}" which is neither "Y" nor "N"')
Hope this helps. You will basically be filtering by following relationships between your models, using double-underscores to move between models, and possibly annotating and filtering on the anotation, or doing things with Q objects and suchlike.
I have the following model
class customer_prices(models.Model):
user = models.ForeignKey(User, on_delete = models.CASCADE,null=True)
price = models.FloatField()
image = models.FloatField()
function = models.TexField()
.
.
(10 more fields)
The fields shown in the homepage is only price thus the other fields are assigned manually, based on the values in a dataframe returned by a self-written some_util_function() e.g
#login_required
def add_price(request):
cleaned_data = form.cleaned_data
df = some_util_function(cleaned_data["price"])
form.user_id = user.id
form.image= df["image"]
.
.
form.save()
messages.success(request, "Price added")
return redirect("my_html")
return render(...)
As we can see each form-field is updated by form.field=df["field"] thus I wonder, if there is another (better way) of doing that?
I have thought about the two following ways:
Instead of form.field=value then form.cleaned_data["field"] = value
Since I have all the data in a dataframe, simply push that dataframe to the given DB e.g df.to_sql("my_table_name").
I know (2) is working, but I think it's better to keep the database changes to Django, and not some mix between pushing data self and let Django handle it.
So right now I'm editting the Querydict that the modelform gives to the view to make the submission in one field all lowercase and have no spaces. but then when I construct and pass that dictionary back to the Modelform to be validated/saved it doesn't give me an error if the same thing has been entered more than once. It seems like unique=True should work for all submissions that are in the correct format not just ones from request.POST. Any help/insight on the issue would be awesome.
EDIT: CODE
THE VIEW THAT HANDLES THE MODELFORM
dict = {}
sitename = request.POST['sitename']
#insert an if statement telling them only letters are allowed
urltitle = ''.join(sitename.split()).lower()
dict['sitename'] = urltitle
make = MakesiteForm(dict)
if make.is_valid():
make.save()
MODEL IN QUESTION
class Makesite(models.Model):
sitename = models.CharField(max_length=100, unique = True)
siteinfo = models.ManyToManyField(Siteinfo)
ref_id = models.ManyToManyField(RefID)
def __unicode__(self):
return u'%s' %(self.sitename)
1.Don't reassign built-in dict function
2.Field processing logic should be done in clean method:
class MakesiteForm(forms.ModelForm):
# your code... Then
def clean_sitename(self):
sitename = self.cleaned_data['sitename']
return ''.join(sitename.split()).lower()
3.Show what errors you get if form is not valid?
Ok, I've been crawling google and Django documentation for over 2 hours now (as well as the IRC channel on freenode), and haven't been able to figure this one out.
Basically, I have a model called Room, which is displayed below:
class Room(models.Model):
"""
A `Partyline` room. Rooms on the `Partyline`s are like mini-chatrooms. Each
room has a variable amount of `Caller`s, and usually a moderator of some
sort. Each `Partyline` has many rooms, and it is common for `Caller`s to
join multiple rooms over the duration of their call.
"""
LIVE = 0
PRIVATE = 1
ONE_ON_ONE = 2
UNCENSORED = 3
BULLETIN_BOARD = 4
CHILL = 5
PHONE_BOOTH = 6
TYPE_CHOICES = (
('LR', 'Live Room'),
('PR', 'Private Room'),
('UR', 'Uncensored Room'),
)
type = models.CharField('Room Type', max_length=2, choices=TYPE_CHOICES)
number = models.IntegerField('Room Number')
partyline = models.ForeignKey(Partyline)
owner = models.ForeignKey(User, blank=True, null=True)
bans = models.ManyToManyField(Caller, blank=True, null=True)
def __unicode__(self):
return "%s - %s %d" % (self.partyline.name, self.type, self.number)
I've also got a forms.py which has the following ModelForm to represent my Room model:
from django.forms import ModelForm
from partyline_portal.rooms.models import Room
class RoomForm(ModelForm):
class Meta:
model = Room
I'm creating a view which allows administrators to edit a given Room object. Here's my view (so far):
def edit_room(request, id=None):
"""
Edit various attributes of a specific `Room`. Room owners do not have
access to this page. They cannot edit the attributes of the `Room`(s) that
they control.
"""
room = get_object_or_404(Room, id=id)
if not room.is_owner(request.user):
return HttpResponseForbidden('Forbidden.')
if is_user_type(request.user, ['admin']):
form_type = RoomForm
elif is_user_type(request.user, ['lm']):
form_type = LineManagerEditRoomForm
elif is_user_type(request.user, ['lo']):
form_type = LineOwnerEditRoomForm
if request.method == 'POST':
form = form_type(request.POST, instance=room)
if form.is_valid():
if 'owner' in form.cleaned_data:
room.owner = form.cleaned_data['owner']
room.save()
else:
defaults = {'type': room.type, 'number': room.number, 'partyline': room.partyline.id}
if room.owner:
defaults['owner'] = room.owner.id
if room.bans:
defaults['bans'] = room.bans.all() ### this does not work properly!
form = form_type(defaults, instance=room)
variables = RequestContext(request, {'form': form, 'room': room})
return render_to_response('portal/rooms/edit.html', variables)
Now, this view works fine when I view the page. It shows all of the form attributes, and all of the default values are filled in (when users do a GET)... EXCEPT for the default values for the ManyToMany field 'bans'.
Basically, if an admins clicks on a Room object to edit, the page they go to will show all of the Rooms default values except for the 'bans'. No matter what I do, I can't find a way to get Django to display the currently 'banned users' for the Room object. Here is the line of code that needs to be changed (from the view):
defaults = {'type': room.type, 'number': room.number, 'partyline': room.partyline.id}
if room.owner:
defaults['owner'] = room.owner.id
if room.bans:
defaults['bans'] = room.bans.all() ### this does not work properly!
There must be some other syntax I have to use to specify the default value for the 'bans' field. I've really been pulling my hair out on this one, and would definitely appreciate some help.
Thanks!
UPDATE
lazerscience actually helped me find the solution in one of his comments. Basically, the way it works is if you pass a list of primary keys. To make it work I had to change:
if room.bans:
defaults['bans'] = room.bans.all() ### this does not work properly!
to
if room.bans:
defaults['bans'] = [b.pk for b in room.bans.all()]
And bam, it instantly started working (when I view the page, it will show a selectable list of Callers, with the already banned callers already highlighted (selected).
You probably need to use "initial": Django set default form values