change the values in django-CodePudding

i build an application, React Native as Frontend and Django as Backend, i use axios to take data from user then send it to backend.

the user has to choose one of these type [ balance, savaing, income, loans, expenses]

i want the value of [ balance] increasing and decreasing depend of other types the savaing, income increasing the value of balance. and loans, expenses decreasing the value of balance .

i am not sure if i have to do the mathematical on the front-end while axios data or on the model on the backend.

the transactions model

from datetime import date
from tkinter import CASCADE
from django.db import models
from authentication.models import User


# Create your models here.


class Transaction(models.Model):

    TYPE_OPTIONS = [
        ('BALANCE', 'BALANCE'),
        ('SAVING', 'SAVING'),
        ('LOANS', 'LOANS'),
        ('INCOME', 'INCOME'),
        ('EXPENSES', 'EXPENSES')
    ]

    type = models.CharField(choices=TYPE_OPTIONS, max_length=255)
    amount = models.CharField(max_length=255)
    owner = models.ForeignKey(User, on_delete=models.CASCADE)
    category = models.CharField(max_length=255)
    date = models.CharField(max_length=255)


class FinancialDeateails(models.Model):
    balance = models.IntegerField(max_length=255)
    savaing = models.IntegerField(max_length=255)
    income = models.IntegerField(max_length=255)
    loans = models.IntegerField(max_length=255)
    expenses = models.IntegerField(max_length=255)
    owner = models.OneToOneField(User, on_delete=models.CASCADE)

CodePudding user response：

No sure what you need, may be something like this:

class Kind(models.Model):
    label = models.CharField(max_length=255)
    value = models.CharField(max_length=255)

    TYPE_OPTIONS = [
        ('BALANCE', 'BALANCE'),
        ('SAVING', 'SAVING'),
        ('LOANS', 'LOANS'),
        ('INCOME', 'INCOME'),
        ('EXPENSES', 'EXPENSES')
    ]

    @classmethod
    def initial(cls):
        if not cls.objects.exists():
            cls.objects.bulk_create([cls(label=k, value=v) for k, v in cls.TYPE_OPTIONS])

    def __str__(self):
        return self.label


class Transaction(models.Model):
    type = models.ForeignKey(Kind, on_delete=models.CASCADE)
    amount = models.CharField(max_length=255)
    owner = models.ForeignKey(User, on_delete=models.CASCADE)
    category = models.CharField(max_length=255)
    date = models.CharField(max_length=255)

CodePudding user response：

Do you want to increase or decrease the value of balance from FinancialDeateails when the user will change the value of type in Transaction?

If I get it correctly then you have to make a one-to-one relationship with FinancialDeateails and FinancialDeateails.

Then you can override the save method and increase or decrease the value as per the Transaction type.