I am working on a payment system that is registering transactions and timestamps. I would like to make a test to ensure that transactions are only made on a past date - it should not be possible to have a transaction with a future date.
models.py
20 class Ledger(models.Model):
19 account = models.ForeignKey(Account, on_delete=models.PROTECT)
18 transaction = models.ForeignKey(UID, on_delete=models.PROTECT)
17 amount = models.DecimalField(max_digits=10, decimal_places=2)
16 timestamp = models.DateTimeField(auto_now_add=True, db_index=True)
15 text = models.TextField()
14
13 #classmethod
12 def transfer(cls, amount, debit_account, debit_text, credit_account, credit_text, is_loan=False) -> int:
11 assert amount >= 0, 'Negative amount not allowed for transfer.'
10 with transaction.atomic():
9 if debit_account.balance >= amount or is_loan:
8 uid = UID.uid
7 cls(amount=-amount, transaction=uid, account=debit_account, text=debit_text).save()
6 cls(amount=amount, transaction=uid, account=credit_account, text=credit_text).save()
5 else:
4 raise InsufficientFunds
3 return uid
2
1 def __str__(self):
122 return f'{self.amount} :: {self.transaction} :: {self.timestamp} :: {self.account} :: {self. text}'
I honestly don't even know where to start testing this class because Testing is very new to me. I have tested some things I saw online close to the below, but cannot see anything happening. Does it make any sense? Maybe there is something that makes more sense testing here instead... Suggestions are more than welcome!
tests.py
class LedgerModelTestCase(TestCase):
# def setUp(self):
1 # no data to test yet
2 def transfer_completed(self):
3 time = timezone.now() + datetime.timedelta(days=30)
4 print(time)
5 future_transfer = Ledger(timestamp=time)
6 print(future_transfer)
7 self.assertIs(future_transfer.was_published_recently(), False)
8
Related
I require a query that can search my model for the latest, unique records and return a queryset of the results.
I need distinct on setup_name and latest on updated
models.py
class VehicleSetupModel(models.Model):
inertia = models.IntegerField()
tyre_pressure = models.IntegerField()
class StandardVehicleSetupModel(VehicleSetupModel):
setup_name = models.CharField(max_length=20)
updated = models.DateTimeField(auto_now=True)
vehicle = models.ForeignKey(VehicleModel, on_delete=models.CASCADE)
What I've tried
I tried the following:
StandardVehicleSetupModel.objects.all().order_by('updated').distinct('setup_name')
but MySQL does not support DISTINCT ON querys.
Table Layout (DD-MM-YYYY)
setup_name | updated | vehicle
----------------------------------------------------------
TEH 10-10-2020 1
TEH 11-10-2020 1
TEL 10-10-2020 1
TEL 08-10-2020 1
TEL 01-10-2020 1
TEP 01-10-2020 1
Expected Result (DD-MM-YYYY)
setup_name | updated | vehicle
----------------------------------------------------------
TEH 11-10-2020 1
TEL 10-10-2020 1
TEP 01-10-2020 1
Yes, MySQL doesn't support distinct() with arguments. We can use another way:
from django.db.models import Max
results = (
StandardVehicleSetupModel.objects
.values('setup_name')
.annotate(max_id=Max('id'))
.values_list('max_id', 'setup_name')
.order_by('max_id')
)
Not tested yet, but it should work ^^
Scenario: Showing all voucher that a user can apply.
I have 2 tables Voucher (with all information of a voucher) and VoucherCustomer (listing number of vouchers that a user has used)
A validation voucher that can show to user on the application should be
Within use-able duration
Do not exceed number of times used within a day
Do not exceed number of times used per user
Do not exceed number of times used for a voucher
Must active
Here is my model:
class Voucher(models.Model):
code = models.ForeignKey('VoucherCustomer', related_name= 'voucher_code', on_delete = models.CASCADE) (1)
start_at = models.DateTimeField() (2)
end_at = models.DateTimeField() (3)
usage_limit_per_customer = models.BigIntegerField() (4)
times_used = models.BigIntegerField() (5)
usage_limit_daily = models.BigIntegerField() (6)
times_used_daily = models.BigIntegerField() (7)
is_global = models.BooleanField(blank=True, null=True) (8)
is_active = models.BooleanField() (9)
class VoucherCustomer(models.Model):
voucher_code = models.CharField(max_length = 255, primary_key=True) (1)
customer_id = models.IntegerField() (2)
times_used = models.BigIntegerField(blank=True, null=True) (3)
created_at = models.DateTimeField(blank=True, null=True) (4)
updated_at = models.DateTimeField(blank=True, null=True) (5)
Here is the sample data:
+++++++ Voucher ++++++++
(1) (2) (3) (4) (5) (6) (7) (8) (9)
TEST01 | 2020-11-30 17:00:00 | 2021-03-01 16:59:59 | 100 | 1124 | 5000 | 6 | true | true
+++++++ VoucherCustomer ++++++++
(1) (2) (3) (4) (5)
TEST01 10878 9 2020-12-03 02:17:32.012722 2020-12-08 10:32:03.877349
TEST01 12577 1 2020-12-02 07:17:34.005964 2020-12-02 07:17:34.005964
TEST01 8324 18 2020-12-02 07:49:37.385682 2021-02-01 14:35:38.096381
TEST01 7638 2 2020-12-02 08:17:46.532566 2020-12-02 08:17:46.532566
TEST01 3589 1 2020-12-02 14:57:01.356616 2020-12-02 14:57:01.356616
My expected query:
SELECT v.*
FROM leadtime.voucher v
LEFT JOIN leadtime.voucher_customer vc ON v.code = vc.voucher_code AND vc.customer_id in ({input_customer_id})
WHERE 1=1
AND v.start_at <= CURRENT_TIMESTAMP
AND v.end_at >= CURRENT_TIMESTAMP
AND v.is_active = TRUE
AND v.times_used < v.usage_limit
AND v.times_used_daily < v.usage_limit_daily
AND (v.customer_id = {input_customer_id} OR v.is_global)
AND COALESCE(vc.times_used,0) < usage_limit_per_customer
ORDER BY created_at
Here is my code on Django:
from django.db.models import Q, F, Value
from django.db.models.functions import Coalesce
now = datetime.now()
customer_input = customer_id = request.GET.get('customer_id')
query = Voucher.objects.filter(
start_at__lte = now,
end_at__gte = now,
is_active = True,
times_used__lt = F('usage_limit'),
times_used_daily__lt = F('usage_limit_daily'),
Q(customer_id = customer_id_input ) | Q(is_global = True),
VoucherCustomer__customer_id = customer_id_input ,
Coalesce(VoucherCustomer__times_used, Value(0)) <= F('usage_limit_per_customer')
).order_by('created_at').values()
Obviously, it does not work.
I got this error:
File "/code/app_test/views.py", line 467
).order_by('created_at').values()
^
SyntaxError: positional argument follows keyword argument
Anyway, since I am just a beginner, if there are parts that I could improve in my code please feel free to tell me.
------------ Updated ----------------
The current code is not working as I received this err
Cannot resolve keyword 'VoucherCustomer' into field. Choices are: airport, arrival_airport, code, code_id, content, created_at, customer_id, delivery_type, departure_airport, description, discount_amount, discount_type, end_at, from_time, id, is_active, is_global, max_discount_amount, start_at, times_used, times_used_daily, tittle, to_time, updated_at, usage_limit, usage_limit_daily, usage_limit_per_customer
I tried to change the model of VoucherCustomer into this one but still not working.
class VoucherCustomer(models.Model):
voucher_code = models.ManyToOneRel(field = "voucher_code", field_name = "voucher_code", to = "")
......................
class Meta:
managed = False
db_table = 'voucher_customer'
The code is not syntetically correct, you can't use <= inside a method signature, ie use that in filter(), also you need to pass the arguments before passing the keyword arguments through the function, ie some_function(a, b, x=y).
But, you can use Coalesce to annotate the value with Voucher queryset then run the filter again, like this:
query = Voucher.objects.filter(
Q(customer_id = customer_id_input ) | Q(is_global = True),
start_at__lte = now,
end_at__gte = now,
is_active = True,
times_used__lt = F('usage_limit'),
times_used_daily__lt = F('usage_limit_daily'),
code__customer_id = customer_id_input
).annotate(
usage_so_far=Coalesce('code__times_used', Value(0))
).filter(
usage_so_far__gte=F('usage_limit_per_customer')
).order_by('created_at').values()
I'm working with django and mysql.
Say there's a table as below:
class OrderInfo(models.Model):
gg_account_id = models.CharField(max_length=45, blank=True, null=True)
order_status = models.IntegerField(blank=True, null=True)
gg_status = models.IntegerField(blank=True, null=True)
uid = models.IntegerField(blank=True, null=True)
class Meta:
managed = False
db_table = 'order_info'
And data saved in it are:
id gg_account_id order_status gg_status uid
1 6270491342 2 0 1
2 12321323 2 0 34
3 12321323 2 0 34
4 55551233 1 0 54
5 55551233 2 0 54
6 55551233 2 0 54
7 55551233 2 0 54
If there are more than one data with same gg_account_id I want to get only one of them. My expected output should be like :
1 6270491342 1
2 12321323 34
5 55551233 54
and here's my trial with orm query:
recharge_account_list = OrderInfo.objects.\
filter(order_status=2, gg_status=0).\
distinct("gg_account_id").\
values_list("gg_account_id", "uid", "id")
print(recharge_account_list)
But I got error always
File "D:\virtual\Envs\smb_middle_server\lib\site-packages\django\db\backends\base\operations.py", line 171, in distinct
_sql
raise NotSupportedError('DISTINCT ON fields is not supported by this database backend')
django.db.utils.NotSupportedError: DISTINCT ON fields is not supported by this database backend
How can I get expected result?
Thanks
Solution 1: use forloop
gg_account_ids = set()
recharge_accounts = []
for i in recharge_account_list:
if i[0] not in gg_account_ids:
gg_account_ids.add(i[0])
recharge_accounts.append(i)
recharge_account_list = recharge_accounts
Solution 2: use raw SQL
recharge_account_list = OrderInfo.objects.raw('SELECT ... FROM Order_info GROUP BY ...')
It can be observed that you are using mysql as a database.
However, MySQL does not support distinct on the field. I mean by distinct('field_name') it only supports generic distinct So you can do only distinct() operation but not on specific fields.
distinct documentation Django
Similar question
Furthermore, you can achieve that by using group by specific fields.
Distinct with groupby
Let's say I have two models in my app: Car and CarAvailability.
class Car(Model):
availability = ForeignKey(CarAvailability)
class CarAvailability(Model):
WEEKDAYS = (
('monday', 'Monday'),
('tuesday', 'Tuesday'),
('wednesday', 'Wednesday')
# ... basically all the days of the week
)
day = CharField(max_length=20, choices=WEEKDAYS)
What are my options to limit the amount of foreign keys (availability attribute) to a maximum of 7 and make sure of only one per weekday.
I don't know if I'm making myself clear enough here, let me know if anything.
I think you can improve the modeling by using two models Car and DayOfWeek and model this as a ManyToManyField:
class DayOfWeek(models.Model):
name = models.CharField(max_length=20)
def __str__(self):
return self.name
class Car(models.Model):
days = models.ManyToManyField(DayOfWeek)
an alternative modeling could be to use an integer, and encode it a a "bitstring":
from enum import IntFlag
class Day(IntFlag):
MONDAY = 1
TUEDAY = 2
WEDNESDAY = 4
THURSDAY = 8
FRIDAY = 16
SATURDAY = 32
SUNDAY = 64
class Car(models.Model):
days = models.IntegerField()
You can then encode this as:
Car.object.create(days=Day.MONDAY|Day.FRIDAY)
to encode that a car is available on monday and friday.
I created a wold map based web app, when user clicks on a particular country it return information related to a particular country:
The model running behind the app is:
Models.py
from __future__ import unicode_literals
from django.db import models
class Country(models.Model):
name = models.CharField(max_length=200)
def __unicode__(self):
return self.name
class CountryDetails(models.Model):
country = models.ForeignKey(Country)
T_attack = models.PositiveIntegerField(verbose_name="attack")
year = models.CharField(max_length=254)
Deaths = models.CharField(max_length=254)
NEWS_ID = models.CharField(max_length=254, verbose_name="NEWS_ID")
def __unicode__(self):
return self.Deaths
And holds data like given bellow, which is a Demo data faded by admin user interface:
name T_attack year Deaths News_ID
India 12 2006 12 NDTV
India 110 2009 1 DEAN
PAKISTAN 9 2002 10 XYZT
PAKISTAN 11 2021 11 XXTV
India 12 2023 120 NDNV
India 10 2012 12 DEAN
PAKISTAN 12 2022 12 DLRS
Canada 1 2001 1 DLTV
USA 2 2011 13 NTTV
I have completed the app now I have a .csv file that contains data in similar format and around 500 rows.
In few posts, I have seen some suggestions which says django-import-export is a right choice for this purpose but, unfortunately I am not able to implement the import method of "Django-import-export" for this purpose.
hence, I decides to write a manual code to loop over all the rows using "Django-shell" like this
f = open(my_csv_file.csv)
lines = f.readlines()
For i,l in enumerate(lines):
l.split(',')[0]
c = Country.objects.create(name=l.split(',')[0])
CountryDetails.objects.create(country=c,T_attack=l.split(',')[1],year=l.split(',')[2],Deaths=l.split(',')[3],News_ID=l.split(',')[4])
But this method massed up the scenario and not able to add the data as I had added with Admin inter phase manually.