I am modelling an accounting system. I have the following models:
class GeneralAccount(MPTTModel):
parent = TreeForeignKey('self', on_delete=models.CASCADE, null=True, blank=True, related_name='children')
name = models.CharField(max_length=100, verbose_name='Account Name')
code = models.CharField(max_length=10, verbose_name='Account Code')
balance = models.DecimalField(max_digits=9, decimal_places=2)
class InventoryAccount(GeneralAccount):
description = models.TextField()
price = models.DecimalField(max_digits=9, decimal_places=2)
cost = models.DecimalField(max_digits=9, decimal_places=2)
available_stock = models.DecimalField(max_digits=9, decimal_places=2)
value = models.DecimalField(max_digits=9, decimal_places=2)
class JournalEntry(models.Model):
transaction_date = models.DateField(verbose_name='Transaction Date', default=django.utils.timezone.now)
account_from = models.ForeignKey(GeneralAccount, on_delete=models.PROTECT) # THIS IS THE PROBLEM
account_to = models.ForeignKey(GeneralAccount, on_delete=models.PROTECT) # THIS IS THE PROBLEM
amount = models.DecimalField(max_digits=9, decimal_places=2, blank=True, null=True)
My problem is in the account_from/account_to fields.
Currently, it is only accepting a GeneralAccount but I also want it to accept an InventoryAccount because essentially it is an MPTTModel/GeneralAccount with just some specialized fields.
The only thing I can think of is to create a separate JournalEntry class for Inventory but I would prefer just to streamline it. Actually, if I could have only one MPTT model (i.e One Account Model) that would be preferrable.
Is there way around this?
P.S. I have checked several accounting github repos but essentially they are not implementing a subsidiary ledger accounts. They are all general ledger accounts. The separate InventoryAccount class is my attempt to implement a subsidiary ledger.
