(Django) Delete function does not remove data from database

Question

Currently I'm having a table that shows the list of drugs. This table has a delete button in every data row. When I click it, the row does not go away.

I tried the same delete syntax (in the function called 'destroy') in Django shell and it worked. I just don't understand why when I clicked on the Remove button inside the template, nothing happened, even after refreshing.

drugs/views.py

from django.shortcuts import render, redirect
from django.views.generic import ListView
from .models import (
    Drug,
)
from .forms import (
    DrugForm,
)
def add_drug(request):
    forms = DrugForm()
    if request.method == 'POST':
        forms = DrugForm(request.POST)
        if forms.is_valid():
            drug_id = forms.cleaned_data['drug_id']
            name = forms.cleaned_data['name']
            drug_type = forms.cleaned_data['drug_type']
            Drug.objects.create(drug_id=drug_id, name=name, 
                                drug_type=drug_type)
            return redirect('drug-list')
    context = {
        'form': forms
    }
    return render(request, 'drugs/add_drug.html', context)    
def destroy(request, drug_id):  
    d = Drug.objects.get(drug_id=drug_id)  
    d.delete()  
    d.save()
    return redirect("/")     
class DrugListView(ListView):
    model = Drug
    template_name = 'drugs/drug_list.html'
    context_object_name = 'drug'

ddms/urls.py

from django.contrib import admin
from django.urls import path, include
# local
from .views import base, dashboard
from drugs.views import destroy


urlpatterns = [
    path('admin/', admin.site.urls),
    path('', dashboard, name='dashboard'),
    path('drugs/', include('drugs.urls')),
    path('delete/', destroy), 
]

templates/drugs/drug_list.html


    
        
                    {% comment %}  {% endcomment %}
                    
                {% if drug %}
                {% for drug in drug %}
                
                    {% comment %}  {% endcomment %}
                    
                {% endfor %}
                {% else %}
                    
                {% endif %}
            
            
                # ID
                    Name
                    Type
                    ACTION
                
            
            {{ forloop.counter }} {{ drug.drug_id }}
                    {{ drug.name }}
                    {{ drug.drug_type }}
                    
                        
                            
                            
                                Edit
                                Remove
                            
                        
                    
                
No Drug Data

drugs/models.py

from django.db import models
from .drug_types import drug_types_list


class Drug(models.Model):
    drug_id = models.CharField(max_length=20)
    name = models.CharField(max_length=50, unique=True)
    drug_type = models.CharField(max_length=20, choices=drug_types_list, default='pills')
    def __str__(self):
        return self.name

My guess is if the function in views.py is not at fault then could the problem lies inside my template, within the Remove button?

I have just started building a project with Django and out of all CRUD templates I find this one most simplistic. Before this, I tried the module DeleteView, object.save() after deletion, checking my html,... unfortunately no error messsage popped up for this one.

Could you show me the way to solve this?

user_67579 · Answer

You should not save the drug, since then you create a new record again with the same items:

def destroy(request, drug_id):
    d = Drug.objects.get(drug_id=drug_id)
    d.delete()  
    # no d.save()
    return redirect('/')

Furthermore you should create, update and remove entities with a POST request, not a GET request: GET requests are supposed to be safe.

You can thus restrict access to the view with the @require_POST [Django-doc]:

from django.shortcuts import get_object_or_404
from django.views.decorators.http import require_POST

@require_POST
def destroy(request, drug_id):
    d = get_object_or_404(Drug, drug_id=drug_id)
    d.delete()
    return redirect('/')

and use a mini form on the HTML page instead of a link:

method="POST" action="/delete/{{ drug.drug_id }}/">

user_10164597 · Answer

Don't save after delete object, because if you're save that data it'll create that same data in new 'id'. try this, It'll work...

def destroy(request, drug_id):  
    d = Drug.objects.get(drug_id=drug_id)  
    d.delete()
    return redirect("/")

user_11422689 · Answer

Combining with the first answer from @Willem Van Onsem, I modified my urls.py path to destroy function as:

path('delete//', destroy)

with int replaced as string and included a slash / at the end of the url

(Django) Delete function does not remove data from database

3 Answers