Database migration failed

[zongxindu]

I just followed the installation steps. when I am running this command:
python manage.py migrate
The program throws an exception：
django.core.exceptions.ImproperlyConfigured: Set the SECRET_KEY environment variable
This is defined in the setting.py file：
SECRET_KEY = env('SECRET_KEY')
I don't know how to solve this problem, then randomly generated a string of text as the SECRET_KEY：
SECRET_KEY='2ap4_#)wk@5)3lsh6idzxwaouy6)*(5z#w(3atk0%a5!+-29j-
but, when I am running the command: python manage.py migrate
The program throws another exception：
django.core.exceptions.ImproperlyConfigured: Set the DATABASE_URL environment variable
I am sorry, I tried to learn the basics of Django, but I didn't know anything about Web development, or database, and after looking at some of the basics of Django, I still didn't know how to Debug this error.