django.core.exceptions.ImproperlyConfigured: mysqlclient 1.3.13 or newer is required; you have 0.9.3

Pycharm2019.1.1初次配置mysql，不要用PyMySQL 0.9.3

涉及环境

• PyCharm 2019.1.1
  Build #PY-191.6605.12, built on April 3, 2019
  JRE: 11.0.2+9-b159.34 amd64
  JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
• Windows 10 1809
• Django version 2.2.2
• Python 3.7.1
• mysqlclient 1.4.2.post1
• MySQL Community Server 8.0.16

测试过程

PyCharm默认的Virtualenv用来隔离测试项目很不错。
在新建Django项目后，SQLite配置成mysql。

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'testdatabase',
        'USER': 'root',
        'PASSWORD': 'root',
        'HOST': '127.0.0.1',
        'PORT': '3306',
    }
}

shift+F10，我艹，出错了！

Watching for file changes with StatReloader
Exception in thread django-main-thread:
Traceback (most recent call last):
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\db\backends\mysql\base.py", line 15, in <module>
    import MySQLdb as Database
ModuleNotFoundError: No module named 'MySQLdb'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Program Files\Python37\lib\threading.py", line 917, in _bootstrap_inner
    self.run()
  File "C:\Program Files\Python37\lib\threading.py", line 865, in run
    self._target(*self._args, **self._kwargs)
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\utils\autoreload.py", line 54, in wrapper
    fn(*args, **kwargs)
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\core\management\commands\runserver.py", line 109, in inner_run
    autoreload.raise_last_exception()
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\utils\autoreload.py", line 77, in raise_last_exception
    raise _exception[1]
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\core\management\__init__.py", line 337, in execute
    autoreload.check_errors(django.setup)()
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\utils\autoreload.py", line 54, in wrapper
    fn(*args, **kwargs)
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\apps\registry.py", line 114, in populate
    app_config.import_models()
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\apps\config.py", line 211, in import_models
    self.models_module = import_module(models_module_name)
  File "C:\Program Files\Python37\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 728, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\contrib\auth\models.py", line 2, in <module>
    from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\contrib\auth\base_user.py", line 47, in <module>
    class AbstractBaseUser(models.Model):
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\db\models\base.py", line 117, in __new__
    new_class.add_to_class('_meta', Options(meta, app_label))
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\db\models\base.py", line 321, in add_to_class
    value.contribute_to_class(cls, name)
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\db\models\options.py", line 204, in contribute_to_class
    self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\db\__init__.py", line 28, in __getattr__
    return getattr(connections[DEFAULT_DB_ALIAS], item)
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\db\utils.py", line 201, in __getitem__
    backend = load_backend(db['ENGINE'])
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\db\utils.py", line 110, in load_backend
    return import_module('%s.base' % backend_name)
  File "C:\Program Files\Python37\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "D:\Exercises\PycharmProjects\Virtualenv\test620\lib\site-packages\django\db\backends\mysql\base.py", line 20, in <module>
    ) from err
django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module.
Did you install mysqlclient?

这一看不是没有导入MySQLdb module么？

原因分析

很多教程中说python版本支持之类的，
导入的PyMySQL 0.9.3，
配置里安装下。
再在Django的__init__.py中加入如下代码：

import pymysql
pymysql.install_as_MySQLdb()

成功了？却不是我。
我的却出现了以下错误。

django.core.exceptions.ImproperlyConfigured: mysqlclient 1.3.13 or newer is required; you have 0.9.3.

感觉这是历史遗留了的最大的坑，

到底是什么鬼？

解决方案

不要搞PyMySQL，我就爱原生方法。

1. PyCharm的Settings里直接安装mysqlclient 1.4.2.post1。
2. shift+F10 测试下，搞定。

终于可以正常玩儿了。

附赠个Database面板连接MySQL时，需要在URL后面加上?开始的神奇字符，连不上的时候试试吧，完整URL如下：

jdbc:mysql://localhost:3306/youdatabasename?useUnicode=true&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC