Error when Django form try tu update data - django-models

Question

I am very new in django.
Situation is like this
I have a model
class Slotmodels (models.Model):
modelid = models.AutoField(primary_key=True)
model_desc = models.TextField()
categoryid = models.ForeignKey(categories, on_delete=models.CASCADE)
shopid = models.ForeignKey(shops, on_delete=models.CASCADE)
brandid = models.ForeignKey(brands, on_delete=models.CASCADE)
reference = models.CharField(max_length=50,null=True)
history = models.TextField(null=True)
year = models.IntegerField(null=True)
purchase_price = models.FloatField(default=0)
actual_price = models.FloatField(default=0)
limited_edition = models.BooleanField(null=False,default=False)
color = models.CharField(max_length=50,null=True)
number = models.IntegerField(null=True)
livery = models.CharField(max_length=50,null=True)
sponsor = models.CharField(max_length=50,null=True)
scale = models.CharField(max_length=10,null=True)
engine = models.CharField(max_length=20,null=True)
eng_position = models.CharField(max_length=20,null=True)
crown = models.IntegerField(null=True)
pinion = models.IntegerField(null=True)
crown_bnd = models.CharField(max_length=20,null=True)
pinion_bnd = models.CharField(max_length=20,null=True)
active = models.BooleanField(default=True)
chasis = models.CharField(max_length=20,null=True)
rear_axis = models.CharField(max_length=30,null=True)
front_axis = models.CharField(max_length=30,null=True)
front_tire_diam = models.IntegerField(null=True)
rear_tire_diam = models.IntegerField(null=True)
front_tire_width = models.IntegerField(null=True)
rear_tire_width = models.IntegerField(null=True)
collection_desc = models.CharField(max_length=30,null=True)
bench_desc = models.CharField(max_length=30,null=True)
Total_weight = models.IntegerField(null=True)
def __str__(self):
return self.modelid, self.model_desc
With a form based on that model:
class FormAltaSlotModel(ModelForm):
class Meta:
model = Slotmodels
fields = ['modelid','model_desc','categoryid','shopid','brandid','reference','history','year','purchase_price',
'actual_price','limited_edition','color','number','livery','sponsor','scale','engine','eng_position',
'crown','pinion','crown_bnd','pinion_bnd','active','chasis','rear_axis','front_axis','front_tire_diam',
'rear_tire_diam','front_tire_width','rear_tire_width','collection_desc','bench_desc','Total_weight']
help_texts = {
}
widgets = {
'history': Textarea(attrs={'cols': 30, 'rows': 2}),
'model_desc': Textarea(attrs={'cols': 30, 'rows': 2})
}
When I instance the form to create a record, is everything ok!. It is important to say that I have three foreignkey fields so when I render the form , the list values of the model referenced appear in the screen. And, the values are recorded properly (in the related Id fields).
The point is when I tried to update a record previously recorded. In the screen appear the descriptions and the list is not appearing, then the values that are passed to the form are descriptions instead of the codes, so the message "Select a valid choice. That choice is not one of the available choices.", appear for the three foreignkey fields that are 'categoryid','shopid','brandid'.
I have tried to fix it, but with no success. Thanks in advance!

Answer 1

Here I tried to do full CRUD with your MODEL & MODELFORM
view.py
def InsertData(request):
my_data = Slotmodels.objects.all() # Show data of Student Table
if request.method == 'POST':
form = FormAltaSlotModel(request.POST,request.FILES)
if form.is_valid():
form.save()
messages.success(request,'Student Successfully Inserted')
return redirect('/')
else:
form = FormAltaSlotModel()
context= {'form':form,'my_data':my_data}
return render(request,'home.html',context)
def UpdateData(request,modelid):
my_data = Slotmodels.objects.all() # Show data of Student Table
set_student = Slotmodels.objects.get(modelid=modelid)
if request.method == 'POST':
form = FormAltaSlotModel(request.POST,request.FILES,instance=set_student)
if form.is_valid():
form.save()
messages.success(request,'Student Successfully Updated')
return redirect('/')
else:
form = FormAltaSlotModel(instance=set_student)
context= {'form':form,'my_data':my_data}
return render(request,'home.html',context)
def DeleteData(request,modelid):
set_student = Slotmodels.objects.get(modelid=modelid)
set_student.delete()
messages.success(request,'Student Successfully Deleted')
return redirect('/')
urls.py
urlpatterns = [
path('', InsertData,name='insert_data'),
path('up/<int:modelid>/', UpdateData,name='update_data'),
path('del//<int:modelid>/', DeleteData,name='delete_data'),
]
HTML Code
<div class="container my-5">
<div class="row">
<div class="col-12">
<form action="" method="POST">
{% csrf_token %}
{{form.as_p}}
<button type="submit">Add</button>
</form>
</div>
<div class="col-12">
<table class="table">
<thead>
<tr>
<th scope="col">No.</th>
<th scope="col">Categories</th>
<th scope="col">Shops</th>
<th scope="col">Brands</th>
<th scope="col">Actions</th>
</tr>
</thead>
<tbody>
{% for i in my_data %}
<tr>
<td>{{forloop.counter}}</td>
<td>{{i.categoryid}}</td>
<td>{{i.shopid}}</td>
<td>{{i.brandid}}</td>
<td>
Update
Delete
</td>
</tr>
{% endfor %}
</tbody>
</table>
</div>
</div>
</div>
Output