1. Create a category model
class Category(models.Model):
name = models.CharField(max_length=50, blank=True, null=True)
def __str__(self):
return self.name2. Make migration and migrate
3. If you have any data in the existing Stock table, you will need to insert some data in the category table before proceeding
4. Update the Stock model. Change category from Charfield to ForeignKey
class Stock(models.Model):
category = models.ForeignKey(Category, on_delete=models.CASCADE)5. Chose a default ID for existing data in the Category table when prompted (Usually when adding a new field to an existing table that has data)
Hi i really enjoyed your video and it was very helpful.
but adding the foreign key ended up with giving a “FieldError”
Can you please show me the error let me see if I can help?
def list_items(request):
header = ‘List of listed items’
form = StockSearchForm(request.POST or None)
queryset = Stock.objects.all()
context = {
‘header’: header,
‘queryset’: queryset,
‘form’: form,
}
if request.method == “POST”:
queryset = Stock.objects.filter(category__name__icontains=form[‘category’].value(),
item_name__icontains=form[‘item_name’].value())
if form[‘export_to_CSV’].value() == True:
response = HttpResponse(content_type=’text/csv’)
response[‘Content-Disposition’] = ‘attachment;filename=”List of stock.csv”‘
writer = csv.writer(response)
writer.writerow([‘CATEGORY’, ‘ITEM_NAME’, ‘QUANTITY’])
instance = queryset
for stock in instance:
writer.writerow([stock.category, stock.item_name, stock.quantity])
return response
context = {
‘header’: header,
‘queryset’: queryset,
‘form’: form,
}
return render(request, ‘list_items.html’, context)
Thanks for sharing
hey
i really liked your tutorials but i am now facing some errors .
after adding the drop down choice list now we cannot add new categories and we have to move to admin panel to add it and after adding the foreign key we cannot add other items to the same categories and when we try to add it by making it as a string it says that category already exists
please help me I really need to study this project.
thank you
There is a validation on the data_entry form definition. Remove it and it will let you add products with the same category
Hi its really good. But I too got the “FieldError”.
Can you please help me through. Thanks!
What is the error?
Hello. After this modification, ocorrurs this error:
TypeError at /add_items/
unsupported operand type(s) for +: ‘Category’ and ‘str’
Request Method: POST
Request URL: http://127.0.0.1:8000/add_items/
Django Version: 2.2
Exception Type: TypeError
Exception Value:
unsupported operand type(s) for +: ‘Category’ and ‘str’
You are trying to concatenate and Object(Category) and a String. You will need to convert Category object to like this: str(Category)
Hi sir
It’s very helpful for django beginners..
With clear expectations and code notes..
I’m student and started learning python django through your YouTube channel…
I stuck in stock management system project..
Video lecture 21 …
I request you to please share me the complete code…
So I will continue for learning…
Thank you once again for helping students with free of cost…
All the codes are here on the site. Just follow the numbers you will get all you need
I am making good progress upto this point
Nice! keep pushing
Good evening Sir!
please After changing my models to a ForeignKey and also after registering the Admin with the category, My list_Items start coming up with errors like
OperationalError at /list_items/
no such column: stockmgmt_stock.category_id
Request Method: GET
Request URL: http://127.0.0.1:8000/list_items/
Django Version: 3.1.7
Exception Type: OperationalError
Exception Value:
no such column: stockmgmt_stock.category_id
Exception Location: C:\Users\Isibor Gamaliel\Desktop\DjangoApps\stockproject\env\lib\site-packages\django\db\backends\sqlite3\base.py, line 413, in execute
Python Executable: C:\Users\Isibor Gamaliel\Desktop\DjangoApps\stockproject\env\Scripts\python.exe
Python Version: 3.7.6
Python Path:
[‘C:\\Users\\Isibor Gamaliel\\Desktop\\DjangoApps\\stockproject\\src’,
‘C:\\Users\\Isibor Gamaliel\\anaconda3\\python37.zip’,
‘C:\\Users\\Isibor Gamaliel\\anaconda3\\DLLs’,
‘C:\\Users\\Isibor Gamaliel\\anaconda3\\lib’,
‘C:\\Users\\Isibor Gamaliel\\anaconda3’,
‘C:\\Users\\Isibor Gamaliel\\Desktop\\DjangoApps\\stockproject\\env’,
‘C:\\Users\\Isibor ‘
‘Gamaliel\\Desktop\\DjangoApps\\stockproject\\env\\lib\\site-packages’]
Server time: Sun, 28 Feb 2021 22:30:31 +0000
Error during template rendering
In template C:\Users\Isibor Gamaliel\Desktop\DjangoApps\stockproject\src\stockmgmt\templates\list_items.html, error at line 64
no such column: stockmgmt_stock.category_id
54
55
56
57 COUNT
58 CATEGORY
59 ITEM NAME
60 QUANTITY IN STORE
61 DELETE
62
63
The error is indicating to this forloop instance in queryset
64 {% for instance in queryset %}
65
66 {{forloop.counter}}
67 {{instance.category}}
68 {{instance.item_name}}
69 {{instance.quantity}}
70
71
72 {% endfor %}
73
74
While powershell is also showing me this/
return self.cursor.execute(sql, params)
File “C:\Users\Isibor Gamaliel\Desktop\DjangoApps\stockproject\env\lib\site-packages\django\db\backends\sqlite3\base.py”, line 413, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: no such column: stockmgmt_stock.category_id.
please what can i do?
You might need to do a “migrate”
Still Stuck on this page. Try remove last migrations. If Still not working Drop Tables. Then makemigrations. Still not working. Drop database. Just Delete it.
Go for Migrations. All done. Everything working fine.
Hahaha. I like that. Great job
One more thing. Now you don’t need this piece of code
category_choice = (
(‘Furniture’, ‘Furniture’),
(‘IT Equipment’, ‘IT Equipment’),
(‘Phone’, ‘Phone’),
(‘Electronics’, ‘Electronics’),
)
delete it or comment it for another project
Nice job. Keep it up
Hey,
Your videos are really helpful Abdourahman . I am following these as it is.
In this tutorial I’m stuck and I’m not able to find the solution. The problem is that stockmgmt.catogery table is not creating in the database when i m running these commands. I’m a newbie so it might be a small issue. Please reply.
if i use “category = models.ForeignKey(Category,on_delete=models.CASCADE)” showing error
53
54
55 COUNT
56 CATEGORY
57 ITEM NAME
58 QUANTITY IN STORE
59 Delete Items
60
61
62 {% for instance in queryset %}
63
64 {{forloop.counter}}
65 {{instance.category}}
66 {{instance.item_name}}
67 {{instance.quantity}}
68 Delete
69
70 {% endfor %}
71
72
Do you have a Category model?
when i click home page and list_items,add_items showing his error
Quit the server with CTRL-BREAK.
[30/Jun/2021 04:07:31] “GET /list_items/ HTTP/1.1” 200 8084
[30/Jun/2021 04:07:31] “GET /static/css/stylesheet.css HTTP/1.1” 304 0
Not Found: /docs/4.4/dist/js/bootstrap.bundle.min.js
[30/Jun/2021 04:07:31] “GET /docs/4.4/dist/js/bootstrap.bundle.min.js HTTP/1.1” 404 2735
[30/Jun/2021 04:07:34] “GET /update_items/2/ HTTP/1.1” 200 3939
Not Found: /docs/4.4/dist/js/bootstrap.bundle.min.js
[30/Jun/2021 04:07:34] “GET /docs/4.4/dist/js/bootstrap.bundle.min.js HTTP/1.1” 404 2735
[30/Jun/2021 04:07:48] “GET / HTTP/1.1” 200 3410
I guess bootstrap.bundle.min.js is missing. your application can’t find it
FieldError at /list_items/
Related Field got invalid lookup: icontains
Request Method: POST
Request URL: http://127.0.0.1:8000/list_items/
Django Version: 3.2.4
Exception Type: FieldError
Exception Value:
Related Field got invalid lookup: icontains
Exception Location: D:\python program\storestockproject\venv\lib\site-packages\django\db\models\sql\query.py, line 1182, in build_lookup
Python Executable: D:\python program\storestockproject\venv\Scripts\python.exe
Python Version: 3.9.2
Python Path:
[‘D:\\python program\\storestockproject\\venv’,
‘C:\\Users\\ASUS\\AppData\\Local\\Programs\\Python\\Python39\\python39.zip’,
‘C:\\Users\\ASUS\\AppData\\Local\\Programs\\Python\\Python39\\DLLs’,
‘C:\\Users\\ASUS\\AppData\\Local\\Programs\\Python\\Python39\\lib’,
‘C:\\Users\\ASUS\\AppData\\Local\\Programs\\Python\\Python39’,
‘D:\\python program\\storestockproject\\venv’,
‘D:\\python program\\storestockproject\\venv\\lib\\site-packages’]
Server time: Thu, 08 Jul 2021 09:06:04 +0000
Hey, I was following your tutorial no. 21 on Foreign Keys but unfortunately you didn’t illustrate how you went about your views.py to submit form data to the database with a FK. The video where you dealt with the views.py, the category had no FK. I’m working on a similar mini project with a Category as a FK but I’m stuck on how to submit form data to the database because of the category_id that is associated to my given category. Do you have a GitHub repo where I can find the project so that I can follow up with the views.py?
Alternatively you can contribute to my Stack overflow question here (https://stackoverflow.com/questions/68733392/django-null-value-in-column-category-id-of-relation-apis-api-violates-not-n)
Thank you and keep up the good work.