I have the following model.
FRONT_BACK=(('F','Front'), ('B','Back'), ('C','Common'))
PRODUCT_TYPE=(('TL','Tubeless Tyre'), ('TT','Tubed Tyre'), ('NA','Not applicable'))
class Product(models.Model):
product_group=models.ForeignKey('productgroup.ProductGroup', null=False,blank=False)
manufacturer=models.ForeignKey(Manufacturer, null=False,blank=False)
product_type=models.CharField(max_length=2, choices=PRODUCT_TYPE, null=False,blank=False)
wheel_position=models.CharField(max_length=1, choices=FRONT_BACK, null=False,blank=False)
opening_stock=models.PositiveIntegerField(default=0)
stock_in=models.PositiveIntegerField(verbose_name="Stock in so far", default=0)
stock_out=models.PositiveIntegerField(verbose_name="Stock out so far", default=0)
created_by=models.ForeignKey(auth.models.User, default=1)
class Meta:
ordering=['product_group','manufacturer']
unique_together = ('product_group', 'manufacturer','product_type','wheel_position')
The unique_together gives the desired result - when I try to duplicate, I get the message
Product with this Product group, Manufacturer, Product type and Wheel position already exists. -----message(1)
In a combination of (ProductGroup,Manufacturer,ProductType), if a product having product_type NA is present, the system should not permit to add another product with TL or TT for the same (ProductGroup,Manufacturer). Similarly, if a product of type TL/TT is present, an addition of NA (with other values the same) should be prevented.
In a combination of (ProductGroup,Manufacturer,ProductType,WheelPosition), if a product having wheel_position C is present, the system should not permit to add another product with F or B for the same (ProductGroup,Manufacturer,ProductType). Similarly if a product of type F/B is present, and addition of C (with other values the same) should be prevented.
In order to ensure this, I've added a clean() method to my form (which is enclosed below). I think this addition does the desired job however, when the unique_key error occurs, instead of displaying the error message by the form, I get an uncaught integrity error.
IntegrityError at /product/create/1/
duplicate key value violates unique constraint "product_product_product_group_id_manufac_485329c6_uniq" DETAIL: Key (product_group_id, manufacturer_id, product_type, wheel_position)=(1, 1, NA, F) already exists.
def clean(self):
print(self.cleaned_data)
if self.cleaned_data['product_type'] == 'NA':
tl=f=Product.objects.filter(product_group=self.cleaned_data['product_group'],
manufacturer=self.cleaned_data['manufacturer'],
product_type= 'TL')
tt=f=Product.objects.filter(product_group=self.cleaned_data['product_group'],
manufacturer=self.cleaned_data['manufacturer'],
product_type= 'TT')
if tl.exists() :
url = reverse('product_detail', kwargs={'pk': tl[0].id})
raise forms.ValidationError({'product_type':
[mark_safe("<a href=\"%s\">Product Type: TL </a> exists for this combination. N/A is not allowed" % url)]})
elif tt.exists():
url = reverse('product_detail', kwargs={'pk': tt[0].id})
raise forms.ValidationError({'product_type':
[mark_safe("<a href=\"%s\">Product Type: TT </a> exists for this combination. N/A is not allowed" % url)]})
else:
na=f=Product.objects.filter(product_group=self.cleaned_data['product_group'],
manufacturer=self.cleaned_data['manufacturer'],
product_type= 'NA')
if na.exists():
url = reverse('product_detail', kwargs={'pk': na[0].id})
raise forms.ValidationError({'product_type':
[mark_safe('<a href="%s"> Product type N/A </a> already exists for this combination.' % url) ]})
if self.cleaned_data['wheel_position'] == 'C':
f=Product.objects.filter(product_group=self.cleaned_data['product_group'],
manufacturer=self.cleaned_data['manufacturer'],
product_type= self.cleaned_data['product_type'],
wheel_position='F')
b=Product.objects.filter(product_group=self.cleaned_data['product_group'],
manufacturer=self.cleaned_data['manufacturer'],
product_type= self.cleaned_data['product_type'],
wheel_position='B')
if f.exists() :
url = reverse('product_detail', kwargs={'pk': f[0].id})
raise forms.ValidationError({'wheel_position':
[mark_safe("<a href=\"%s\">Wheel position: Front</a> exists for this combination. Common is not allowed" % url ) ]})
elif b.exists():
url = reverse('product_detail', kwargs={'pk': b[0].id})
raise forms.ValidationError({'wheel_position':
[mark_safe("<a href=\"%s\">Wheel position: Back</a> exists for this combination. Common is not allowed" % url )]})
else:
c=Product.objects.filter(product_group=self.cleaned_data['product_group'],
manufacturer=self.cleaned_data['manufacturer'],
product_type= self.cleaned_data['product_type'],
wheel_position='C')
if c.exists():
url = reverse('product_detail', kwargs={'pk': c[0].id})
raise forms.ValidationError({'wheel_position':
[mark_safe("<a href=\"%s\"> Wheel position: Common </a> exists for this combination." % url)]})
Here's query result.
Product.objects.filter(product_group=1, manufacturer=1,product_type='NA')
<QuerySet [<Product: 1000.20.16 (CEAT, NA, F)>,
<Product: 1000.20.16 (CEAT, NA, B)>]>
When I comment the clean() method, the system displays a proper message on unique_key duplication as shown above (---- message 1).
I don't know what I'm missing.
Please help.
Thanks.
You must call super() so that the parent class' clean method runs and checks checks unique constraints.
def clean(self):
cleaned_data = super(MyForm, self).clean()
...
This should prevent the integrity error.