NO.1：
You have 15 unapplied migration(s). Your project may not work properly until you apply the migrations for app(s): admin, auth, contenttypes, sessions.
Run 'python manage.py migrate' to apply them.
解决：执行python manage.py migrate 同步更改数据库表或字段
NO.2:
安装数据库 ModuleNotFoundError: No module named 'ConfigParser'
解决：因为python2和python3的ConfigParser有大小写的区别，修改后就没有问题了。
NO.3:
django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module. Did you install mysqlclient?
解决：django默认数据库sqlite3切换到mysql的错误
1、pip3 install pymysql
2、在项目文件夹中__init__.py增加以下内容：
import pymysql
pymysql.install_as_MySQLdb()
3、重新加载
python3 manage.py makemigrations
python3 manage.py migrate