InlineModelAdmin fails of an empty form when DecimalField has default and blank=True.

[Dmitry Chaplinsky]

I have following code for the model:

class PayrollItem(models.Model):
    payroll = models.ForeignKey(
        "Payroll",
        verbose_name="Payroll",
        on_delete=models.CASCADE,
        related_name="items",
    )
    contract = models.ForeignKey(
        "Contract",
        verbose_name="Contract",
        on_delete=models.CASCADE,
        related_name="payments",
    )
    hours = models.DecimalField("Hours", decimal_places=2, default="0.00", max_digits=7, blank=True)
    current_rate = models.DecimalField(
        "Hourly rate", decimal_places=2, default="0.00", max_digits=7, blank=True
    )

which is then added as an InlineModelAdmin:

class PayrollItemInline(admin.TabularInline):
    extra = 1
    model = PayrollItem

when I hit save parent object, Django raises validation error for foreign key of an empty inline form like in attached file

If I exclude "hours", "current_rate" everything works as expected!

[Dmitry Chaplinsky]

Validation error

[Mariusz Felisiak]

Thanks for this report, however your models configuration allows for such behavior. If a field has blank=True form validation will allow entry of an empty value (see ​blank documentation) and default will not be used because value (empty) is provided (see ​default documentation). In the same time you have NOT NULL constraint in a database.

Closing per TicketClosingReasons/UseSupportChannels.