一、执行makemigrations命令
在让Django与MySQL关联后，要让Python也和MySQL连接上，需要在虚拟环境中执行makemigrations命令
(fswy) xxxxdeMacBook-Pro:blog xiatian$ python3 manage.py makemigrations
二、报错
后面报了一系列的错误，在此做个总结
错误1：Error loading MySQLdb module.
Traceback (most recent call last):
File "/Users/xiatian/fswy/lib/python3.8/site-packages/django/db/backends/mysql/base.py", line 16, in <module>
import MySQLdb as Database
ModuleNotFoundError: No module named 'MySQLdb'
......
django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module.
Did you install mysqlclient?
原因：
在Python2中用的是MySQLdb，但在Python3中用的是 mysqlclient
解决方案：
安装mysqlclient
(fswy) xxxxdeMacBook-Pro:blog xiatian$ pip3 install mysqlclient
Collecting mysqlclient
Successfully installed mysqlclient-1.4.6
重现输入:$ python3 manage.py makemigrations
错误2：Reason: image not found
File "/Users/xiatian/fswy/lib/python3.8/site-packages/MySQLdb/__init__.py", line 18, in <module>
from . import _mysql
ImportError: dlopen(/Users/xiatian/fswy/lib/python3.8/site-packages/MySQLdb/_mysql.cpython-38-darwin.so, 2): Library not loaded: @rpath/libmysqlclient.21.dylib
Referenced from: /Users/xiatian/fswy/lib/python3.8/site-packages/MySQLdb/_mysql.cpython-38-darwin.so
Reason: image not found
原因：未在_ _ init_ _.py文件伪装MySQL数据库
这里死的很惨，试过各种方法
安装各种模块：
$ pip3 install mysql-connector-python-rf
$ pip3 install mysql-python
$ pip3 install MySQLdb
不过，好像都是python2.x的解决方案，这里都不支持python3.8
解决方案：伪装mysql数据库
来到App文件夹下面的 _ _ init_ _.py文件，在里面直接添加如下代码：
import pymysql
pymysql.install_as_MySQLdb()
效果如下：
重现输入:$ python3 manage.py makemigrations
错误3：mysqlclient 1.3.13 or newer is required
django.core.exceptions.ImproperlyConfigured: mysqlclient 1.3.13 or newer is required; you have 0.9.3.
原因：
由于上面安装的pymysql版本低，但是python3又不支持高版本，所以只能靠改变设置文件来更改配置了
解决方案：
进入/Users/xiatian/fswy/blog/venv/lib/python3.8/site-packages/django/db/backends/mysql/base.py中将其第36、37行注释掉
重现输入:$ python3 manage.py makemigrations
发现还是报错同样的错误
解决方案：
打开访达，前往：/Users/xiatian/fswy/blog/venv/lib/python3.8/site-packages/django/db/backends/mysql/base.py，发现base.py中并没有被注释掉第36、37行，这里用文本编辑打开，再次注释掉第36、37行。
重现输入:$ python3 manage.py makemigrations
错误4： Warning: 3135
/Users/xiatian/fswy/lib/python3.8/site-packages/pymysql/cursors.py:170: Warning: (3135, "'NO_ZERO_DATE', 'NO_ZERO_IN_DATE' and 'ERROR_FOR_DIVISION_BY_ZERO' sql modes should be used with strict mode. They will be merged with strict mode in a future release.")
原因：
中文意思是：警告:(3135，"‘NO_ZERO_DATE’， ‘NO_ZERO_IN_DATE’和’ error_for_division on_by_zero ’ sql模式应该与严格模式一起使用。它们将在未来的版本中与strict模式合并。”
就是说SQL modes应该使用安全模式，即该功能将可能在未来的版本中被舍弃或者合并，这是MySQL向后兼容常见的处理方式
解决方案：
把setting里的options注释掉就正常了
重现输入:$ python3 manage.py makemigrations
错误5：No changes detected
No changes detected
原因：
有时执行python manage.py makemigrations命令(也可能人比较皮，把migrations文件夹给删了)，会提示"No changes detected."
解决方案：
先python3 manage.py makemigrations --empty yourappname生成一个空的initial.py
(fswy) xxxxdeMacBook-Pro:blog xiatian$ python3 manage.py makemigrations --empty fswy
Migrations for 'fswy':
fswy/migrations/0001_initial.py
再python3 manage.py migrate 创建数据库表单
(fswy) xxxxdeMacBook-Pro:blog xiatian$ python3 manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, firstWEB, sessions
Running migrations:
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying admin.0001_initial... OK
Applying admin.0002_logentry_remove_auto_add... OK
Applying admin.0003_logentry_add_action_flag_choices... OK
Applying contenttypes.0002_remove_content_type_name... OK
Applying auth.0002_alter_permission_name_max_length... OK
Applying auth.0003_alter_user_email_max_length... OK
Applying auth.0004_alter_user_username_opts... OK
Applying auth.0005_alter_user_last_login_null... OK
Applying auth.0006_require_contenttypes_0002... OK
Applying auth.0007_alter_validators_add_error_messages... OK
Applying auth.0008_alter_user_username_max_length... OK
Applying auth.0009_alter_user_last_name_max_length... OK
Applying auth.0010_alter_group_name_max_length... OK
Applying auth.0011_update_proxy_permissions... OK
Applying firstWEB.0001_initial... OK
Applying sessions.0001_initial... OK
至此，终于将Python3.8和MySQL8.0连接。
希望此文能给予大家帮助！
参考网址：
Mac下python3安装mysqlclient
python3 manage.py makemigrations执行可能出现的错误
django.core.exceptions.ImproperlyConfigured: mysqlclient 1.3.13 or newer is required; you have 0.9.2
