The default database is SQLite. But if you want to change the database, you could apply the below step, especially for PostgreSQL.
To use PostgreSQL, you need to install it in advance.
1. Settings.py
2. Command Line
$ python manage.py migrate
2.1 Error case 1)
If ‘python manage.py migrate‘ doesn’t work, you have to install the required pip package. In my case, I installed psycopg2.
$ pip install psycopg2
2.2 Error case 2)
If it still doesn’t work, check whether you wrote the appropriate upper case and lower case. I could solve the error through this method.