Some Migration errors in Django 🤯 (emotional long post)

30.10.201920.03.2020 djangokatyaLeave a comment

You ran makemigrations, then migrate and yet Django dares to throw an error? Incomparable betrayal! Let’s look through several cases.

Sidenote

For ages encountering migrations errors, I have been wipin the entire database and migrations files. Until one day an error occurred at a production server. There was no other option but to calm down and learn how to fix it.

M2M relation to itself through another model // 1-minute guide 🐍↩️

29.10.201905.11.2019 djangokatyaLeave a comment

Say, you want your Tag model to contain a subtags field that has Tag instances. And you need to make a through table.

GenericView: Attributeerror ‘list’ object has no attribute ‘filter’ // 1-second guide 😮💢

21.10.201915.09.2020 djangokatya2 Comments

So you are casually overriding get_queryset() in a, say, ListView, like this:

def get_queryset(self):
    entries = [x for x in Entry.objects.all() if x.publications]
    return entries

Because you need to sort the Entry table by a reverse M2M relation publications and then BAM!:

Attribute error 'list' object has no attribute 'filter'

Without a trace of the line you made a mistake in…

Copyable table column // 1-minute guide 🌺 🐋

16.10.201929.10.2019 djangokatyaLeave a comment

I like Excel for the ability to copy the whole column, and HTML tables don’t normally provide that. As a result, tons of time and nerves spent on copying cell by cell, cell by cell…

My friend and colleague (who btw likes HTML tables but in Adobe Dreamweaver graphic mode) needs a lot of data searched and sorted and put in table, but also copyable. Hm…

So, let’s make HTML tables great!

sidenote In my examples, tables are light blue, and cells are pink.