Form redirection error doesn't work

Using Django
1

Hi, continuing to the old solved problem click here.

in this issue, I have a condition in my Model.py that just one item is related to one invoice only.

so I made this condition in the model.py

class Invoice_billing(models.Model):
    Invoce_Nbr = models.ForeignKey(Invoices, on_delete=models.CASCADE) # should be Actived
    Item_Ctra  = models.ForeignKey(contrat_items, on_delete=models.CASCADE) # should be Actived
    Unites     = models.DecimalField(max_digits=15, decimal_places=2,null=True)
    Discu      = models.DecimalField(max_digits=4, decimal_places=2, default=0)
    post_date  = models.DateTimeField(default=timezone.now)
    author     = models.ForeignKey(User,on_delete=models.CASCADE)
    def __str__(self):
        return self.Invoce_Nbr.Invoce_Nbr
    def get_absolute_url(self):
        return reverse('Contrat_detail')
    class Meta:
        ordering = ('-post_date',)
        unique_together=[['Invoce_Nbr', 'Item_Ctra']]

so when I duplicate an item it doesn’t redirect me to the same page.
it gives me this error page.

# IntegrityError at /Invoic_billing/1/

UNIQUE constraint failed: Home_invoice_billing.Invoce_Nbr_id, Home_invoice_billing.Item_Ctra_id

I want to redirect it to the same page with a message as I did in my views.py

    if request.method == 'POST':
        if request.POST.get("form_ability") == "Add":
            form2 =form(request.POST)
            if form2.is_valid():
                form2.instance.Invoce_Nbr_id= id_itm
                form2.instance.author = request.user
                form2.save()
                return redirect('Invoic_billing', id_itm)
            else:
                form_error_ablt = 'Check your inputs'

what I missed here?

2

In your model you have:

So this error occurs:

Because of this:

(emphasis mine)

You can’t duplicate an item because you explicitly told the database to not allow two rows where both the Invoce_Nbr and Item_Ctra are the same.

3

Yes Mr, I knew , but my question is how to return back to my page without save the form and without getting the page error?

4

You’ve got at least two different ways of handling this -

1 Like
5

Thank you it works with try

    if request.method == 'POST':
        if request.POST.get("form_ability") == "Add":
            form2 =form(request.POST)
            try:
                if form2.is_valid():
                    form2.instance.Invoce_Nbr_id= id_itm
                    form2.instance.author = request.user
                    form2.save()
                    return redirect('Invoic_billing', id_itm)
            except:
                form_error_ablt = 'Check your inputs "duplicated item"'