how would I go about automatically generating a list of objects in the database for DJango?
Example model:
#models.py
class Book(models.Model):
BOOKS = (
('0','Secret Life of Bees'),
('1','Pride and Prejudice')
)
name = models.CharField(max_length=100, choices=BOOKS)
def __str__(self):
return self.name
class Library(models.Model):
librarian = models.OneToOneField(UserProfile, on_delete=models.CASCADE, primary_key=True)
books = models.ManyToManyField(Book)
How would I automatically add all the books to the database so I don't have to manually add them using the admin control panel?
Update! To anyone who doesn't know how to do this, you can call Object.objects.bulk_create(Object([Object(property=propertyInfo),Object(property=propertyInfo)]).
Related
I have a comparable setup as the documentation of django describes for a many to one scenario.
https://docs.djangoproject.com/en/3.0/topics/db/examples/many_to_one/
from django.db import models
class Reporter(models.Model):
first_name = models.CharField(max_length=30)
last_name = models.CharField(max_length=30)
email = models.EmailField()
def __str__(self):
return "%s %s" % (self.first_name, self.last_name)
class Article(models.Model):
headline = models.CharField(max_length=100)
pub_date = models.DateField()
reporter = models.ForeignKey(Reporter, on_delete=models.CASCADE)
def __str__(self):
return self.headline
class Meta:
ordering = ['headline']
I have situations where the Reporter does not yet exist, but Article can be created for a non-existing reporter, so I want the Article model to make a Reporter if it doesn't exist yet. I guess what I need is a check if the Reporter already exists and if not create a new one. Is this the best way? Or does Django have a better, build in, method for this? Al reporters will have specific ID that is
I very new to Django and have trouble finding resources about this, probably because I'm missing terminology, so I some can point me in the right direction I would already be helped!
You're looking for the get_or_create or update_or_create function.
reporter, created_reporter = Reporter.objects.get_or_create(
email=reporter_email,
first_name=reporter_first_name,
last_name=reporter_last_name,
)
reporter.articles.create(...)
Additionally, if you make Reporter.email unique you can do the following which is more robust as it takes advantage of your databases uniqueness constraint.
reporter, created_reporter = Reporter.objects.get_or_create(
email=report_email,
defaults={
"first_name": reporter_first_name,
"last_name": reporter_last_name,
}
)
Doing that will check if the reporter exists based on the email and if it doesn't, then it'll create one using the default values.
I am creating my own users, Restaurant and Customer. I have extended the AbstractUser class and then created a OneToOneField field for each user. I am wondering if I need to add the AUTH_USER_MODEL in my settings.py. And also wondering what that does exactly...
What I was planning on doing was adding to my settings.py:
AUTH_USER_MODEL = 'myapp.Customer','myapp.Restaurant'
Do I have the right idea here?
My models.py:
class User(AbstractUser):
is_restaurant = models.BooleanField(default=False)
is_customer = models.BooleanField(default=False)
class Restaurant(models.Model):
user = models.OneToOneField(User, primary_key=True, on_delete=models.CASCADE)
restaurant_name = models.CharField(max_length=50)
def __str__(self):
return self.restaurant_name
class Customer(models.Model):
user = models.OneToOneField(User, primary_key=True, on_delete=models.CASCADE)
address = models.CharField(max_length=200)
def __str__(self):
return self.user.get_full_name()
No. AUTH_USER_MODEL isn't expecting a tuple, so this won't work.
In any case, Restaurant and Customer are not your user model; your subclassed User is. That's what you should be putting in that setting.
I would suggest create single user table instead of three different tables and add type as restaurant, customer, admin etc. And add only one table into settings file. this won't lead any further issues authentication etc. Having single user table is always robust. In your case having three tables seems not good to maintain.
========== UPDATE ===========
Create model for user named as CustomUser (or name which you feel better) and extends to User Model of Django using AbstractBaseUser,PermissionsMixin. like
class CustomUser(AbstractBaseUser): have all fields which user table has already. and add your desired table to bifurcate type of restaurant and
customer have type field with choices option.
For further help you can check section https://docs.djangoproject.com/en/1.11/topics/auth/customizing/#substituting-a-custom-user-model
I have a m2m relationship between Servers and Products in Django with a through table called ServerProducts.
class ServerProduct(TimeStampedModel):
# Additional fields may be required in the future
server = models.ForeignKey('Server', on_delete=models.CASCADE)
product = models.ForeignKey('Product', on_delete=models.CASCADE)
class Server(TimeStampedModel):
name = models.CharField(max_length=35)
# ...
products = models.ManyToManyField('Product', through='ServerProduct',
related_name='products', blank=True)
class Product(TimeStampedModel):
name = models.CharField(max_length=45, unique=True)
# ...
servers = models.ManyToManyField(
'Server', through='ServerProduct', related_name='servers')
In my view I have a form which allows users to create a Server and select from a list of all products for the Server to be associted with.
In order to create the ServerProduct objects (for the through table) on each save I have to write the following code inside save().
class ServerForm(forms.ModelForm):
class Meta:
model = Server
fields = '__all__'
def save(self, commit=True):
instance = super(ServerForm, self).save(commit=False)
instance.save()
if instance.products.count():
instance.products.clear()
for product in self.cleaned_data['products']:
ServerProduct.objects.create(server=instance, product=product)
return instance
I want to be able to reuse the form for both Create and Update views. Hence why I have to check if the current Server is associated with any products, and then do instance.products.clear(). To make sure it removes any previous products if they get deselected by a user.
This entire process feels unecessary, especially when I've read a lot about Django's built-in form.save_m2m() method. My question is, is there a simpler way do achieve what I'm doing using Django built-in's?
Is there a way in Django to have multiple objects stored and manageable (in Django admin) inside another object?
Example, I have two models: Items and RMA. The RMA may have multiple Items inside of it. Each Item is unique in the sense that it is an inventoried part, so I can't just reference the same item multiple times with foreignKey (though maybe I'm misunderstanding its use/implementation).
So for now, I have an Item model:
class Item(models.Model):
serial_number = models.CharField(max_length=200)
name = models.CharField(max_length=200)
part_number = models.CharField(max_length=200)
location = models.CharField(max_length=200)
def __unicode__(self):
return self.name
And an RMA model:
class RMA(models.Model):
number = models.AutoField(primary_key=True)
items = ?????
Ultimately I'd like to be able to maintain use of the Django admin functionality to add/remove items from an RMA if necessary, so I've been staying away from serializing a list and then deserializing on display. Any help would be much appreciated.
You're modeling a has-many relationship.
This would be modeled with a Foreign Key on Item to RMA:
class Item(models.Model):
serial_number = models.CharField(max_length=200)
name = models.CharField(max_length=200)
part_number = models.CharField(max_length=200)
location = models.CharField(max_length=200)
rma = models.ForeignKey(RMA)
def __unicode__(self):
return self.name
To make it accessible in the admin of RMA you need djangos InlineAdmin functionality.
You can find examples in the django tutorial part2.
You are effectively describing a Many-To-One relation and to do this you are going to have to add the ForeignKey reference to the Item model, not to the RMA model.
You can also add a related_name to give the RMA model an attribute that you can call.
For example:
class Item(models.Model):
rma = models.ForeignKey(RMA,related_name="items")
serial_number = models.CharField(max_length=200)
# etc...
To manage the creation of these, you'll need an InlineModelAdmin form, so your admin.py file will need to look like this:
from django.contrib import admin
class ItemInline(admin.TabularInline):
model = Item
class RMAAdmin(admin.ModelAdmin):
inlines = [
ItemInline,
]
I have the following models
class Group(models.Model):
name = models.CharField(max_length=32, unique=True)
class Subgroup(models.Model):
name = models.CharField(max_length=32, unique=True)
group = models.ForeignKey(Group)
class Keywords(models.Model):
name = models.CharField(max_length=32, unique=True)
subgroup = models.ForeignKey(Subgroup)
For each Subgroup I need to manage a list of keywords.
I'm trying to use django forms to automatically display a list (select box) where if I add or remove values to that list and then issue a form.save that it automatically updates the models and data.
How exactly can I do this? Are my models designed properly to allow this?
I think you can create form with MultipleChoiceField:
class MyForm(forms.Form):
to_select = forms.MultipleChoiceField(widget=forms.CheckboxInput, choices=[])
In this case you have to override form`s save method.
Did you try to create model form for subgroup class?
class MyForm(forms.ModelForm):
class Meta():
model=Subgroup