To reverse all migrations for an app, you can run:

python manage.py migrate my_app zero

Issues:

I want to recreate the migrations, so I deleted files under migrations folder, and drop the database. And try this python manage.py makemigrations, it reponse No changes detected.

Fix:

Create the database again, and clear files and folders under migrations, then try the following:

1. python manage.py makemigrations --empty appname
2. python manage.py makemigrations
3. python manage.py migrate

It works!

Background

mysql server was installed by brew install mysql

Issues like this:

ERROR: Failed building wheel for mysqlclient

ld: library not found for -lssl
clang: error: linker command failed with exit code 1 (use -v to see invocation)
error: command 'clang' failed with exit status 1

Exception: Wrong MySQL configuration: maybe https://bugs.mysql.com/bug.php?id=86971 ?

In the Django's tutorial, I created an app name front, and its urls.py definition like this:

from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path('front/', include('front.urls')),
    path('admin/', admin.site.urls),
]

So, if the app's url in web browser is http://127.0.0.1:8000/front/
In fact, most website the home page won't have subdirectory. So, the solutions is here:

from django.contrib import admin
from django.urls import path, include, re_path

urlpatterns = [
    re_path(r'^', include('front.urls')),
    path('front/', include('front.urls')),
    path('admin/', admin.site.urls),
]

Now, you can visit the app root url in the home page. http://127.0.0.1:8000/