Storing lists of words in database - best practice - database

I'm implementing a user filter system on a website. Users are to be able to select 'categories' and 'packages' of interest to them and have the matching data presented when they log in. Both sets of data will come from HTML select forms eg. Categories: 'null pointers', 'dead code'... and packages 'package_x', 'package_y', 'package_z'...
My question is about the best way to store this list information in a database (I am using Django and PostgresSQL).
My initial thought is to have a table like this:
user_id - one to one field
categories - textfield - store json data
packages - textfield - store json data
Is there a better way to be doing this?

I would go the route of using a user profile with categories and packages being many to many fields.
In models.py
from django.contrib.auth.models import User
class Category(models.Model):
name = models.CharField(max_length=255)
class Package(models.Model):
name = models.CharField(max_length=255)
class UserProfile(models.Model):
user = models.ForiegnKey(User)
categories = models.ManyToManyField(Category)
packages = models.ManyToManyField(Package)
In admin.py
from django.contrib.auth.admin import UserAdmin
from django.contrib.auth.models import User
class CustomUserAdmin(UserAdmin):
inlines = [UserProfile]
#filter_horizontal = ('',) #Makes the selection a bit more friendly
admin.site.unregister(User)
admin.site.register(User, CustomUserAdmin)
In views.py
user_with_profile = User.objects.get(pk=user_id).get_profile()
All that being said. Django 1.5 will replace the user profile with being able to use a configurable user model.

Related

How to create ArrayField in TortoiseORM

How to create ArrayField() in TortoiseORM
from common.base_model import AbstractBaseModel
from tortoise.fields import CharField, BooleanField, ForeignKeyField, ArrayField
class City(AbstractBaseModel):
name = CharField(max_length=100, unique=True)
district = CharField(max_length=100, null=True)
state = CharField(max_length=100)
country = ArrayField() # not working
is_verified = BooleanField(default=True)
There is no ArrayField in TortoiseORM, here is an article about fields in TortoiseORM from its documentation.
As you can see, there is no matching field in TortoiseORM, so you have to extend the existing field class.
I suggest extending the basic class Field because your subclass' to_db_value method has to return the same type as extended field class' to_db_value method, and in the class Field it's not specified.
Next time, try harder - read the documentation and make better questions (add more info, show your attempts).
To achieve the result you want,which I'm assuming is having a field to hold multiple countries, you'd have to create another table for your country field and have a many to many relationship between that table and your city table,its a more conventional implementation that wont have you extend the existing field class.

Can I use a recursive ParentalKey in Wagtail?

Say I have the following model in a Wagtail app:
# models.py
from django.db import models
from django.db.models.deletion import CASCADE
from wagtail.admin.edit_handlers import InlinePanel, FieldPanel
from modelcluster.models import ParentalKey, ClusterableModel
class Person(ClusterableModel):
name = models.CharField(max_length=300)
contact_for = ParentalKey(
'self', on_delete=CASCADE, null=True, related_name='contacts'
)
panels = [
FieldPanel('name'),
FieldPanel('contact_for'),
InlinePanel('contacts')
]
And the following hooks:
# wagtail_hooks.py
from wagtail.contrib.modeladmin.options import ModelAdmin, modeladmin_register
from home.models import Person
class PersonAdmin(ModelAdmin):
model = Person
menu_label = 'People'
menu_icon = 'list-ul'
menu_order = 200
add_to_settings_menu = False
exclude_from_explorer = False
list_display = ('name',)
search_fields = ('name',)
list_filter = ('contact_for',)
modeladmin_register(PersonAdmin)
When running the above and navigating to Admin > People > Add Person I will get a RecursionError exception (maximum recursion depth exceeded).
I'm guessing this is a Wagtail related issue, because I can use the class as intended in IPython:
./manage.py shell -i ipython
In [1]: from home.models import Person
In [2]: mike = Person(name='Mike')
In [3]: mike.contacts = [Person(name='Sam'), Person(name='John')]
In [4]: mike.contacts
Out[4]: <modelcluster.fields.create_deferring_foreign_related_manager.<locals>.DeferringRelatedManager at 0x7f36e9548af0>
In [5]: mike.save()
In [6]: [person.name for person in Person.objects.all()]
Out[6]: ['Mike', 'Sam', 'John']
In [7]: Person.objects.all()[1].contact_for.name
Out[7]: 'Mike'
So, is there a way I can make use of a recursive ParentalKey in Wagtail? What am I doing wrong/missing?
Edit: I just found this answer. So I'm wondering if I should even be trying to use ParentalKey (and ParentalManyToManyField) for non Page models.
Edit 2: For anyone interested, I ended up splitting my Model to avoid a recursive key. InlinePanels do work with ModelAdmin classes, it's just Wagtail doesn't seem to support recursive keys. I have also opted to use Snippets and SnippetChooserPanel where it felt appropriate.
A ParentalKey means that the child model is notionally treated as 'part of' the parent model and doesn't exist as an independent entity - for example, an image gallery being part of a page - for purposes such as versioning, and moderation workflow. (In Wagtail, non-page models handled through snippets or ModelAdmin don't have these features, but in order for them to share the same InlinePanel mechanism as pages, they also use ParentalKey.)
In this case, a Person is not part of another Person, and needs to be editable independently of the 'parent', so a ParentalKey isn't appropriate here. Instead, you should use a ForeignKey, which just indicates some relation between the models. This does mean that you can't use an InlinePanel to manage multiple Person records within the same view - you'll have to edit them separately, and use something like SnippetChooserPanel or a simple dropdown to set up the relations between them.

How to show all fields of model in admin page?

here is the models page
In this picture, only the title shows up on here, I used:
def __unicode__(self):
return self.title;
here is the each individual objects
How do I show all these fields?
How do I show all the fields in each Model page?
If you want to include all fields without typing all fieldnames, you can use
list_display = BookAdmin._meta.get_all_field_names()
The drawback is, the fields are in sorted order.
Edit:
This method has been deprecated in Django 1.10 See Migrating from old API for reference. Following should work instead for Django >= 1.9 for most cases -
list_display = [field.name for field in Book._meta.get_fields()]
By default, the admin layout only shows what is returned from the object's unicode function. To display something else you need to create a custom admin form in app_dir/admin.py.
See here: https://docs.djangoproject.com/en/dev/ref/contrib/admin/#django.contrib.admin.ModelAdmin.list_display
You need to add an admin form, and setting the list_display field.
In your specific example (admin.py):
class BookAdmin(admin.ModelAdmin):
list_display = ('title', 'author', 'price')
admin.site.register(Book, BookAdmin)
If you want to include all but the ManyToManyField field names, and have them in the same order as in the models.py file, you can use:
list_display = [field.name for field in Book._meta.fields if field.name != "id"]
As you can see, I also excluded the id.
If you find yourself doing this a lot, you could create a subclass of ModelAdmin:
class CustomModelAdmin(admin.ModelAdmin):
def __init__(self, model, admin_site):
self.list_display = [field.name for field in model._meta.fields if field.name != "id"]
super(CustomModelAdmin, self).__init__(model, admin_site)
and then just inherit from that:
class BookAdmin(CustomModelAdmin):
pass
or you can do it as a mixin:
class CustomModelAdminMixin(object):
def __init__(self, model, admin_site):
self.list_display = [field.name for field in model._meta.fields if field.name != "id"]
super(CustomModelAdminMixin, self).__init__(model, admin_site)
class TradeAdmin(CustomModelAdminMixin, admin.ModelAdmin):
pass
The mixin is useful if you want to inherit from something other than admin.ModelAdmin.
I found OBu's answer here to be very useful for me. He mentions:
The drawback is, the fields are in sorted order.
A small adjustment to his method solves this problem as well:
list_display = [f.name for f in Book._meta.fields]
Worked for me.
The problem with most of these answers is that they will break if your model contains ManyToManyField or ForeignKey fields.
For the truly lazy, you can do this in your admin.py:
from django.contrib import admin
from my_app.models import Model1, Model2, Model3
#admin.register(Model1, Model2, Model3)
class UniversalAdmin(admin.ModelAdmin):
def get_list_display(self, request):
return [field.name for field in self.model._meta.concrete_fields]
Many of the answers are broken by Django 1.10. For version 1.10 or above, this should be
list_display = [f.name for f in Book._meta.get_fields()]
Docs
Here is my approach, will work with any model class:
MySpecialAdmin = lambda model: type('SubClass'+model.__name__, (admin.ModelAdmin,), {
'list_display': [x.name for x in model._meta.fields],
'list_select_related': [x.name for x in model._meta.fields if isinstance(x, (ManyToOneRel, ForeignKey, OneToOneField,))]
})
This will do two things:
Add all fields to model admin
Makes sure that there is only a single database call for each related object (instead of one per instance)
Then to register you model:
admin.site.register(MyModel, MySpecialAdmin(MyModel))
Note: if you are using a different default model admin, replace 'admin.ModelAdmin' with your admin base class
Show all fields:
list_display = [field.attname for field in BookModel._meta.fields]
Every solution found here raises an error like this
The value of 'list_display[n]' must not be a ManyToManyField.
If the model contains a Many to Many field.
A possible solution that worked for me is:
list_display = [field.name for field in MyModel._meta.get_fields() if not x.many_to_many]
I like this answer and thought I'd post the complete admin.py code (in this case, I wanted all the User model fields to appear in admin)
from django.contrib import admin
from django.contrib.auth.models import User
from django.db.models import ManyToOneRel, ForeignKey, OneToOneField
MySpecialAdmin = lambda model: type('SubClass'+model.__name__, (admin.ModelAdmin,), {
'list_display': [x.name for x in model._meta.fields],
'list_select_related': [x.name for x in model._meta.fields if isinstance(x, (ManyToOneRel, ForeignKey, OneToOneField,))]
})
admin.site.unregister(User)
admin.site.register(User, MySpecialAdmin(User))
I'm using Django 3.1.4 and here is my solution.
I have a model Qualification
model.py
from django.db import models
TRUE_FALSE_CHOICES = (
(1, 'Yes'),
(0, 'No')
)
class Qualification(models.Model):
qual_key = models.CharField(unique=True, max_length=20)
qual_desc = models.CharField(max_length=255)
is_active = models.IntegerField(choices=TRUE_FALSE_CHOICES)
created_at = models.DateTimeField()
created_by = models.CharField(max_length=255)
updated_at = models.DateTimeField()
updated_by = models.CharField(max_length=255)
class Meta:
managed = False
db_table = 'qualification'
admin.py
from django.contrib import admin
from models import Qualification
#admin.register(Qualification)
class QualificationAdmin(admin.ModelAdmin):
list_display = [field.name for field in Qualification._meta.fields if field.name not in ('id', 'qual_key', 'qual_desc')]
list_display.insert(0, '__str__')
here i am showing all fields in list_display excluding 'id', 'qual_key', 'qual_desc' and inserting '__str__' at the beginning.
This answer is helpful when you have large number of modal fields, though i suggest write all fields one by one for better functionality.
list_display = [field.name for field in Book._meta.get_fields()]
This should work even with python 3.9
happy coding
I needed to show all fields for multiple models, I did using the following style:
#admin.register(
AnalyticsData,
TechnologyData,
TradingData,
)
class CommonAdmin(admin.ModelAdmin):
search_fields = ()
def get_list_display(self, request):
return [
field.name
for field in self.model._meta.concrete_fields
if field.name != "id" and not field.many_to_many
]
But you can also do this by creating a mixin, if your models have different fields.

Favoriting system on Appengine

I have the following model structure
class User(db.Model) :
nickname = db.StringProperty(required=True)
fullname = db.StringProperty(required=True)
class Article(db.Model) :
title = db.StringProperty(required=True)
body = db.StringProperty(required=True)
author = db.ReferenceProperty(User, required=True)
class Favorite(db.Model) :
who = db.ReferenceProperty(User, required=True)
what = db.ReferenceProperty(Article, required=True)
I'd like to display 10 last articles according to this pattern: article.title, article.body, article.author(nickname), info if this article has been already favorited by the signed in user.
I have added a function which I use to get the authors of these articles using only one query (it is described here)
But I don't know what to do with the favorites (I'd like to know which of the displayed articles have been favorited by me using less than 10 queries (I want to display 10 articles)). Is it possible?
You can actually do this with an amortized cost of 0 queries if you denormalize your data more! Add a favorites property to Authors which stores a list of keys of articles which the user has favorited. Then you can determine if the article is the user's favorite by simply checking this list.
If you retrieve this list of favorites when the user first logs in and just store it in your user's session data (and update it when the user adds/removes a favorite), then you won't have to query the datastore to check to see if an item is a favorite.
Suggested update to the Authors model:
class Authors(db.Model): # I think this would be better named "User"
# same properties you already had ...
favorites = db.ListProperty(db.Key, required=True, default=[])
When the user logs in, just cache their list of favorites in your session data:
session['favs'] = user.favorites
Then when you show the latest articles, you can check if they are a favorite just by seeing if each article's key is in the favorites list you cached already (or you could dynamically query the favorites list but there is really no need to).
favs = session['favs']
articles = get_ten_latest_articles()
for article in articles:
if article.key() in favs:
# ...
I think there is one more solution.
Let's add 'auto increment' fields to the User and Article class.
Then, when we want to add an entry to the Favorite class, we will also add the key name in the format which we will be able to know having auto increment value of the signed in user and the article, like this 'UserId'+id_of_the_user+'ArticleId'+id_of_an_article.
Then, when it comes to display, we will easily predict key names of the favorites and would be able to use Favorite.get_by_key_name(key_names).
An alternative solution to dound's is to store the publication date of the favorited article on the Favorite entry. Then, simply sort by that when querying.

django model/modelForm - How to get dynamic choices in choiceField?

i'm experimenting with django and the builtin admin interface.
I basically want to have a field that is a drop down in the admin UI. The drop down choices should be all the directories available in a specified directory.
If i define a field like this:
test_folder_list = models.FilePathField(path=/some/file/path)
it shows me all the files in the directory, but not the directories.
Does anyone know how i can display the folders?
also i tried doing
test_folder_list = models.charField(max_length=100, choices=SOME_LIST)
where SOME_LIST is a list i populate using some custom code to read the folders in a directory. This works but it doesn't refresh. i.e. the choice list is limited to a snapshot of whatever was there when running the app for the first time.
thanks in advance.
update:
after some thinking and research i discovered what i want may be to either
1. create my own widget that is based on forms.ChoiceField
or
2. pass my list of folders to the choice list when it is rendered to the client
for 1. i tried a custom widget.
my model looks like
class Test1(models.Model):
test_folder_ddl = models.CharField(max_length=100)
then this is my custom widget:
class FolderListDropDown(forms.Select):
def __init__(self, attrs=None, target_path):
target_folder = '/some/file/path'
dir_contents = os.listdir(target_folder)
directories = []
for item in dir_contents:
if os.path.isdir(''.join((target_folder,item,))):
directories.append((item, item),)
folder_list = tuple(directories)
super(FolderListDropDown, self).__init__(attrs=attrs, choices=folder_list)
then i did this in my modelForm
class test1Form(ModelForm):
test_folder_ddl = forms.CharField(widget=FolderListDropDown())
and it didn't seem to work.What i mean by that is django didn't want to use my widget and instead rendered the default textinput you get when you use a CharField.
for 2. I tried this in my ModelForm
class test1Form(ModelForm):
test_folder_ddl = forms.CharField(widget=FolderListDropDown())
test_folder_ddl.choices = {some list}
I also tried
class test1Form(ModelForm):
test_folder_ddl = forms.ChoiceField(choices={some list})
and it would still render the default char field widget.
Anyone know what i'm doing wrong?
Yay solved. after beating my head all day and going through all sorts of examples by people i got this to work.
basically i had the right idea with #2. The steps are
- Create a ModelForm of our model
- override the default form field user for a models.CharField. i.e. we want to explcitly say use a choiceField.
- Then we have to override how the form is instantiated so that we call the thing we want to use to generate our dynamic list of choices
- then in our ModelAdmin make sure we explicitly tell the admin to use our ModelForm
class Test1(models.Model):
test_folder_ddl = models.CharField(max_length=100)
class Test1Form(ModelForm):
test_folder_ddl = forms.choiceField()
def __init__(self, *args, **kwargs):
super(Test1Form, self).__init__(*args, **kwargs)
self.fields['test_folder_ddl'].choices = utility.get_folder_list()
class Test1Admin(admin.ModelAdmin):
form = Test1Form
I use a generator:
see git://gist.github.com/1118279.git
import pysvn
class SVNChoices(DynamicChoice):
"""
Generate a choice from somes files in a svn repo
""""
SVNPATH = 'http://xxxxx.com/svn/project/trunk/choices/'
def generate(self):
def get_login( realm, username, may_save ):
return True, 'XXX', 'xxxxx', True
client = pysvn.Client()
client.callback_get_login = get_login
return [os.path.basename(sql[0].repos_path) for sql in client.list(self.SVNPATH)[1:]]

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