Django foreign key insertion - python

I'm migrating my Python to a REST API, I'm using Django framework 1.8.
I followed the tutorial and one of my requests is to insert an Object (Server) which depends on few fk. In my Python App I normally have 3 queries to insert the records, use RETURNING id to store the Ids of the FKs and finally 1 query to insert my Server object. How can I achieve this in Django?
These are my models and serializer:
serializers.py
#Server Serializer
class ServerSerializer(serializers.ModelSerializer):
owner = serializers.ReadOnlyField(source='owner.username')
class Meta:
model = Server
fields = ('id', 'owner', 'discovered', 'status', 'serialnumber', 'hostname', 'description', 'created')
models.py
class Server(models.Model):
owner = models.ForeignKey('auth.User', related_name='server')
discovered = models.BooleanField(default=False)
status = models.SmallIntegerField(default=0)
serialnumber = models.CharField(max_length=100, null=True)
hostname = models.CharField(max_length=250)
description = models.CharField(max_length=250, blank=True, null=True)
created = models.DateTimeField(auto_now_add=True)
fk_server_model = models.ForeignKey('ServerModel', db_column='fk_server_model')
fk_licensing = models.ForeignKey(Licensing, db_column='fk_licensing', blank=True, null=True)
fk_network_services = models.ForeignKey(NetworkServices, db_column='fk_network_services', blank=True, null=True)
fk_network_interfaces = models.ForeignKey(NetworkInterfaces, db_column='fk_network_interfaces', blank=True, null=True)
fk_server_credentials = models.ForeignKey('ServerCredentials', db_column='fk_server_credentials', blank=True, null=True)
def save(self, *args, **kwargs):
super(Server, self).save(*args, **kwargs)
class Meta:
managed = False
db_table = 'server'

Related

Django: Model does not appear on admin panel

This is the model that I want to show on the admin panel. I'm registering the model via admin.py file with admin.site.register(Ad). I tried to re-write the register line twice, and an exception appeared that the model is already registered.
class Ad(AdModel):
plate = models.CharField(max_length=50, unique=True)
description = models.TextField(max_length=500)
ad_type = models.CharField(
max_length=255,
choices=AdTypes.get_choices(),
default=AdTypes.OFFERING,
)
price = models.PositiveIntegerField(
default=0,
help_text='In cents'
)
location = models.CharField(
max_length=255,
choices=AdLocations.get_choices(),
default=AdLocations.VILNIUS,
)
user = models.ForeignKey(User, on_delete=models.PROTECT)
approved_date = models.DateField(null=True, blank=True)
approved_by = models.ForeignKey(
User, on_delete=models.PROTECT, related_name='approved_by', null=True
)
The two base models:
class UUIDBaseModel(models.Model):
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
uuid = models.UUIDField(default=uuid.uuid4, editable=False, unique=True)
class Meta:
abstract = True
class AdModel(UUIDBaseModel):
expires_at = models.DateTimeField(null=True)
is_draft = models.BooleanField(default=False)
is_active = models.BooleanField(default=False)
class Meta:
abstract = True
This is really strange, maybe that could be the problem because of the naming 'Ad'? I have a serializer for this model and everything works just fine, but the admin panel doesn't want to display it.
views.py
class AdCreateViewSet(ModelViewSet, CreateModelMixin):
serializer_class = AdCreateSerializer
permission_classes = (AllowAny,)
filter_backends = [DjangoFilterBackend]
search_fields = ('plate', 'description', 'user__email')
queryset = Ad.objects.select_related('user')
def perform_create(self, serializer):
user = User.objects.first()
serializer.save(user=user) # self.request.user)
serializers.py
class AdCreateSerializer(CustomAdSerializer):
class Meta:
model = Ad
exclude = ['expires_at']
read_only_fields = ('user',)

Django Rest Framework serialization error: Object of type type is not JSON serializable

I am new to both django and python and currently trying to implement a REST api using django-rest-framework. I know there are a lot of alike questions but they are serializing objects using .json, and i am not.
I have 2 models captain and boat as follows:
//models.py
from django.db import models
class Captain(models.Model):
name = models.CharField(max_length=255, blank=False, unique=False)
last_name = models.CharField(max_length=255, blank=False, unique=False)
government_id = models.CharField(max_length=55, blank=False, unique=True)
company_name = models.CharField(max_length=255, blank=False, unique=False)
phone_number = models.CharField(max_length=55, blank=False, unique=False)
tax_id = models.CharField(max_length=55, blank=False, unique=True)
date_created = models.DateTimeField(auto_now_add=True)
date_modified = models.DateTimeField(auto_now=True)
class Boat(models.Model):
captain = models.ForeignKey(Captain, on_delete=models.CASCADE, null=True, blank=True, related_name='boats')
name = models.CharField(max_length=55, blank=False)
journey_type = models.CharField(max_length=55, null=True, blank=True)
category = models.CharField(max_length=55, null=True, blank=True)
passenger_capacity = models.IntegerField()
crew_count = models.IntegerField()
have_ac = models.IntegerField(default=0)
year_built = models.DateField
year_restored = models.DateField(blank=True)
engine = models.CharField(max_length=255, blank=True, null=True)
generator = models.CharField(max_length=255, blank=True, null=True)
width = models.CharField(max_length=255, null=True)
height = models.CharField(max_length=255, null=True)
length = models.CharField(max_length=255, null=True)
wc_count = models.IntegerField(null=True)
master_cabin_count = models.IntegerField(null=True)
standart_cabin_count = models.IntegerField(blank=False, null=False)
date_created = models.DateTimeField(auto_now_add=True)
date_modified = models.DateTimeField(auto_now=True)
As you can see each boat has one captain and one captain can have many boats. So in database there is a captain_id field for Boat table. I have defined two serializers for each model:
//serializers.py
from rest_framework import serializers
from .models import Captain, Boat
class CaptainSerializer(serializers.ModelSerializer):
class Meta:
model = Captain
fields = ('id', 'name', 'last_name', 'government_id', 'company_name', 'phone_number', 'tax_id', 'date_created', 'date_modified','boats')
class BoatSerializer(serializers.ModelSerializer):
captain = serializers.PrimaryKeyRelatedField(many=False, read_only=True)
class Meta:
model = Boat
fields = ('id', 'captain', 'name', 'journey_type', 'category', 'passenger_capacity', 'crew_count', 'have_ac', 'year_built', 'year_restored', 'wc_count', 'standart_cabin_count')
Then i have defined views for each model.
//views.py
from django.shortcuts import render
from rest_framework import generics
from .serializers import CaptainSerializer, BoatSerializer
from .models import Captain, Boat
class CaptainCreateView(generics.ListCreateAPIView):
queryset = Captain.objects.all()
serializer_class = CaptainSerializer
def perform_create(self, serializer):
serializer.save()
class CaptainDetailsView(generics.RetrieveUpdateDestroyAPIView):
lookup_field = 'pk'
serializer_class = CaptainSerializer
queryset = Captain.objects.all()
class BoatCreateView(generics.ListCreateAPIView):
queryset = Boat.objects.all()
serializer_class = BoatSerializer
def perform_create(self, serializer):
serializer.save()
When i go to page localhost:port/captains/ (or /GET/captains from postman) i can have captain models including the boats he has.
But The problem is : when i go to localhost:port/boats (or postman) it gives,
Object of type type is not JSON serializable
Exception Type: TypeError at /boats/
Exception Value: Object of type type is not JSON serializable
Any ideas how can i fix this? Thanks in advance.
I think the year_built field in the Boat model is not well defined (you're assigning the class DateField but not creating an instance of it):
class Boat(models.Model):
year_built = models.DateField # should be models.DateField()

How to display multiple objects from fields in Django Admin

I am a bit stumped as to how I can add multiple access_token and items_ids in Django Admin. The models and apps involved are as follows. This is my first post so please forgive if it isn't in proper format.
Trans/models.py
class Exchange(models.Model):
created = models.DateTimeField()
owner = models.ForeignKey(settings.AUTH_USER_MODEL, related_name='token', on_delete=models.CASCADE)
access_token = models.CharField(max_length=300, blank=True, default='')
item_id = models.CharField(max_length=300, blank=True, default='')
request_id = models.CharField(max_length=300, blank=True, default='')
class Meta:
ordering = ('item_id',)
I have setup a userprofile section for the admin:
Users/models.py
class UserProfile(models.Model):
user = models.OneToOneField(settings.AUTH_USER_MODEL, primary_key=True, verbose_name='user', related_name='profile', on_delete=models.CASCADE)
avatar_url = models.CharField(max_length=256, blank=True, null=True)
dob = models.DateField(verbose_name="dob", blank=True, null=True)
public_token = models.CharField(max_length=100, blank=True, null=True, verbose_name='public_token')
access_token = models.CharField(max_length=100, blank=True, null=True, verbose_name='access_token')
item_id = models.CharField(max_length=100, blank=True, null=True, verbose_name='item_ID')
just_signed_up = models.BooleanField(default=True)
def __str__(self):
return force_text(self.user)
class Meta():
db_table = 'user_profile'
users/forms.py
class UserProfileForm(forms.ModelForm):
class Meta:
model = UserProfile
fields = ('user', 'public_token', 'access_token', 'item_id',)
users/admin.py
class UserProfileAdmin(admin.ModelAdmin):
search_fields = ('user', 'dob', 'public_token', 'access_token', 'item_id',)
ordering = ('user',)
list_select_related = ('user',)
admin.site.register(UserProfile, UserProfileAdmin)
class UserProfileAdminInline(admin.TabularInline):
model = UserProfile
I'm really just stumped as I tried making many to many field but couldnt seem to link correctly and or the process broke when testing in a sandbox environment. Any help would be greatly appreciated! In my case I need to record multiple access_tokens and item_ids for each user.
It's a little bit confusing what you are asking...particularly the way that your data model is setup....but I'm going to make a couple of assumptions in my answer (it would be helpful to better understand what you are trying to do at a high level).
I think what you are wanting to do is to be able to configure multiple Exchange objects per user profile...in which case I would set things up this way:
1. The related_name field on the FK to the user profile in the exchange model will be how you access multiple exchanges...so in this case you probably want a pluralized name.
2. To be able to edit multiple in the Django Admin you will need to setup an InlineAdmin object.
3. The CharFields that are actually ON the UserProfile will only ever be single fields...if you want multiple then you need to move them to another related object (like the Exchange model).
4. I don't think what you want here is a ManyToMany as that would imply user's would be sharing these tokens and item ids (or Exchanges?)...but maybe that is what you want...in which case you should change the ForeignKey to UserProfile from the Exchange model to a ManyToManyField. The rest of this post assumes you don't want that.
trans/models.py
from django.db import models
from django.conf import settings
class Exchange(models.Model):
class Meta:
ordering = ('item_id', )
created = models.DateTimeField(auto_now_add=True)
owner = models.ForeignKey(settings.AUTH_USER_MODEL, related_name='exchanges', on_delete=models.CASCADE)
access_token = models.CharField(max_length=300, blank=True)
item_id = models.CharField(max_length=300, blank=True)
request_id = models.CharField(max_length=300, blank=True)
users/models.py
from django.db import models
from django.conf import settings
class UserProfile(models.Model):
class Meta:
db_table = 'user_profile'
user = models.OneToOneField(settings.AUTH_USER_MODEL, primary_key=True, verbose_name='user', related_name='profile', on_delete=models.CASCADE)
avatar_url = models.CharField(max_length=256, blank=True)
dob = models.DateField(verbose_name="dob", blank=True, null=True)
public_token = models.CharField(max_length=100, blank=True, null=True)
access_token = models.CharField(max_length=100, blank=True, null=True)
item_id = models.CharField(max_length=100, blank=True, null=True)
just_signed_up = models.BooleanField(default=True)
def __str__(self):
return force_text(self.user)
users/admin.py
from django.contrib import admin
from trans.models import Exchange
from users.models import UserProfile
class ExchangeAdminInline(admin.TabularInline):
model = Exchange
class UserProfileAdmin(admin.ModelAdmin):
inlines = (ExchangeAdminInline, )
search_fields = ('user', 'dob', 'public_token', 'access_token', 'item_id', )
ordering = ('user', )
list_select_related = ('user', )
admin.site.register(UserProfile, UserProfileAdmin)
There is a lot that you can do to configure the inlines to behave how you want...but that's the basics.

Django - Serialize parents associations

I am trying to create a serialized RESTful response from a One to N relationship.
I have a table Lexicon, primary key lexicon_id, I have another table lexicon_attributes, primary key lexicon_attribute_id, foreign key lexicon_id
class Lexicons(models.Model):
"""
Holds all words
"""
lexicon_id = models.BigIntegerField(primary_key=True)
word = models.TextField(blank=True, null=True)
date_created = models.DateTimeField(blank=True, null=True)
date_modified = models.DateTimeField(blank=True, null=True)
class Meta:
managed = True
db_table = 'lexicons'
class LexiconAttributes(models.Model):
class Meta:
managed = True
db_table = 'lexicon_attributes'
lexicon_attribute_id = models.AutoField(primary_key=True)
lexicon_id = models.ForeignKey('Lexicons', db_column='lexicon_id', related_name="lexicon_attributes")
is_verb = models.CharField(max_length=1, blank=True, null=True)
is_plural = models.CharField(max_length=1, blank=True, null=True)
is_past_tense = models.CharField(max_length=1, blank=True, null=True)
serializer
class LexiconAttributesSerializer(serializers.ModelSerializer):
class Meta:
model = LexiconAttributes
fields = '__all__'
class LexiconsSerializer(serializers.ModelSerializer):
lexicon_attributes = LexiconAttributesSerializer(source='*', many=False)
class Meta:
model = Lexicons
When I make a request for /lexicons/2/
{
"lexicon_id": 2,
"lexicon_attributes": {
"lexicon_id": 2
},
"word": "computer",
"date_created": "2015-07-30T20:29:19Z",
"date_modified": "2015-07-30T20:29:19Z"
}
How do I get the other fields in lexicon_attributes table
FYI I am week two into Django, my app was originally done in Cakephp3
class LexiconsSerializer(serializers.ModelSerializer):
lexicon_attributes = LexiconAttributesSerializer()
class Meta:
model = Lexicons
fields = '__all__'
fixed the problem for me after 3 days

DRF - filter across 2 models

I'm working with a legacy database where I have a serializer setup on Table A like so -
class TblapplicationsSerializer(serializers.ModelSerializer):
class Meta:
model = Tblapplications
fields = ('applicationid', 'applicationname', 'description', 'drtierid', 'saglink', 'supportinstructions',
'defaultincidentpriorityid', 'applicationorigintypeid', 'installationtypeid', 'comments',
'lastmodifieddate', 'lastmodifiedby', 'assetstatusid', 'recordownerid', 'adl_app')
depth = 2
I'm using a standard filter -
class TblapplicationsFilter(django_filters.FilterSet):
name = django_filters.CharFilter(name="applicationname", lookup_type="exact")
env = django_filters.CharFilter(name="adl_app__environmentid__domain")
class Meta:
model = Tblapplications
fields = ['applicationname', 'name', 'env']
Here's where it goes sideways. What I want to be able to do is filter on my URL like /api/applications/?name=xxx&env=DEV. It would then return the application and any databases that are linked with the environment of DEV. The name was understandably easy, but the only was I figured out the environment was to make the api point for applications touch the middle table that links the two but it returns multiple values because it's grabbing each time application is referenced with a separate database.
I've updated the Serializer and Filter based on comments given and the serializer, without the &env=DEV returns all the appropriate data (domain is nested in a reverse relationship). I then want my filter to filter the results based on that. Which means that it needs to somehow know to limit the results on the reverse relationship to only what's provided from the nested value.
If you see my models -
class Tblapplicationdatabaselinks(models.Model):
id = models.AutoField(db_column='ID', primary_key=True)
applicationid = models.ForeignKey('Tblapplications', db_column='applicationId', to_field='applicationid',
related_name='adl_app')
dbid = models.ForeignKey('Tbldatabases', db_column='dbId', to_field='id', related_name='adl_db')
environmentid = models.ForeignKey('Tbldomaincodes', db_column='environmentId', to_field='id',
related_name='adl_envlink')
comments = models.TextField(blank=True)
lastmodifieddate = models.DateTimeField(db_column='lastModifiedDate', blank=True, null=True)
lastmodifiedby = models.CharField(db_column='lastModifiedBy', max_length=255, blank=True)
# upsize_ts = models.TextField(blank=True) # This field type is a guess.
class Meta:
managed = False
db_table = 'tblApplicationDatabaseLinks'
class Tblapplications(models.Model):
applicationid = models.AutoField(db_column='applicationId', primary_key=True)
applicationname = models.CharField(db_column='applicationName', max_length=255)
description = models.TextField(blank=True)
drtierid = models.ForeignKey(Tbldomaincodes, db_column='drTierID', blank=True, null=True, to_field='id',
related_name='app_drtier')
saglink = models.TextField(db_column='sagLink', blank=True)
supportinstructions = models.TextField(db_column='supportInstructions', blank=True)
defaultincidentpriorityid = models.IntegerField(db_column='defaultIncidentPriorityId', blank=True, null=True)
applicationorigintypeid = models.IntegerField(db_column='applicationOriginTypeId')
installationtypeid = models.ForeignKey(Tbldomaincodes, db_column='installationTypeId', to_field='id',
related_name='app_insttype')
comments = models.TextField(blank=True)
assetstatusid = models.ForeignKey(Tbldomaincodes, db_column='assetStatusId', to_field='id',
related_name='app_status')
recordownerid = models.ForeignKey(Tblusergroups, db_column='recordOwnerId', blank=True, null=True,
to_field='groupid', related_name='app_owner')
lastmodifieddate = models.DateTimeField(db_column='lastModifiedDate', blank=True, null=True)
lastmodifiedby = models.CharField(db_column='lastModifiedBy', max_length=255, blank=True)
# upsize_ts = models.TextField(blank=True) # This field type is a guess.
class Meta:
managed = False
db_table = 'tblApplications'
class Tbldatabases(models.Model):
dbid = models.AutoField(db_column='dbId', primary_key=True)
dbname = models.CharField(db_column='dbName', max_length=255)
serverid = models.ForeignKey('Tblservers', db_column='serverId', to_field='serverid', related_name='db_serv')
servicename = models.CharField(db_column='serviceName', max_length=255, blank=True)
dbtypeid = models.IntegerField(db_column='dbTypeId', blank=True, null=True)
inceptiondate = models.DateTimeField(db_column='inceptionDate', blank=True, null=True)
comments = models.TextField(blank=True)
assetstatusid = models.IntegerField(db_column='assetStatusId')
recordownerid = models.IntegerField(db_column='recordOwnerId', blank=True, null=True)
lastmodifieddate = models.DateTimeField(db_column='lastModifiedDate', blank=True, null=True)
lastmodifiedby = models.CharField(db_column='lastModifiedBy', max_length=255, blank=True)
# upsize_ts = models.TextField(blank=True) # This field type is a guess.
class Meta:
managed = False
db_table = 'tblDatabases'
class Tbldomaincodes(models.Model):
id = models.IntegerField(db_column='ID', primary_key=True)
domain = models.CharField(primary_key=True, max_length=255)
displayname = models.CharField(db_column='displayName', primary_key=True, max_length=255)
displayorder = models.IntegerField(db_column='displayOrder', blank=True, null=True)
comments = models.TextField(blank=True)
lastmodifieddate = models.DateTimeField(db_column='lastModifiedDate', blank=True, null=True)
lastmodifiedby = models.CharField(db_column='lastModifiedBy', max_length=255, blank=True)
# upsize_ts = models.TextField(blank=True) # This field type is a guess.
class Meta:
managed = False
db_table = 'tblDomainCodes'
Extend your filter set and reference the field in the other model:
class TblapplicationsFilter(django_filters.FilterSet):
name = django_filters.CharFilter(name="applicationname", lookup_type="exact")
env = django_filters.CharFilter(name="environmentid__name")
# ^^^^^^^^^^^^^^^^^^^
class Meta:
model = Tblapplications
fields = ['applicationname', 'name', 'env']
Also, you may wish to name your ForeignKey fields without the id suffix, which is the Django convention. In Django, when you access Tblapplications.environmentid, it is normally a model instance, not the actual id integer itself.

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