在django 添加app 时报错找不到MysqlDB

E:WF_WorkHappyAutoTest>python manage.py startapp userauth
Traceback (most recent call last):
  File "D:Program FilesPython3.6libsite-packagesdjangodbackendsmysqlase.py", line 16, 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 "manage.py", line 21, in <module>
    main()
  File "manage.py", line 17, in main
    execute_from_command_line(sys.argv)
  File "D:Program FilesPython3.6libsite-packagesdjangocoremanagement\__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "D:Program FilesPython3.6libsite-packagesdjangocoremanagement\__init__.py", line 377, in execute
    django.setup()
  File "D:Program FilesPython3.6libsite-packagesdjango\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "D:Program FilesPython3.6libsite-packagesdjangoapps
egistry.py", line 114, in populate
    app_config.import_models()
  File "D:Program FilesPython3.6libsite-packagesdjangoappsconfig.py", line 211, in import_models
    self.models_module = import_module(models_module_name)
  File "D:Program FilesPython3.6libimportlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 978, in _gcd_import
  File "<frozen importlib._bootstrap>", line 961, in _find_and_load
  File "<frozen importlib._bootstrap>", line 950, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 655, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 678, in exec_module
  File "<frozen importlib._bootstrap>", line 205, in _call_with_frames_removed
  File "D:Program FilesPython3.6libsite-packagesdjangocontribauthmodels.py", line 2, in <module>
    from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager
  File "D:Program FilesPython3.6libsite-packagesdjangocontribauthase_user.py", line 47, in <module>
    class AbstractBaseUser(models.Model):
  File "D:Program FilesPython3.6libsite-packagesdjangodbmodelsase.py", line 121, in __new__
    new_class.add_to_class('_meta', Options(meta, app_label))
  File "D:Program FilesPython3.6libsite-packagesdjangodbmodelsase.py", line 325, in add_to_class
    value.contribute_to_class(cls, name)
  File "D:Program FilesPython3.6libsite-packagesdjangodbmodelsoptions.py", line 208, in contribute_to_class
    self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
  File "D:Program FilesPython3.6libsite-packagesdjangodb\__init__.py", line 28, in __getattr__
    return getattr(connections[DEFAULT_DB_ALIAS], item)
  File "D:Program FilesPython3.6libsite-packagesdjangodbutils.py", line 207, in __getitem__
    backend = load_backend(db['ENGINE'])
  File "D:Program FilesPython3.6libsite-packagesdjangodbutils.py", line 111, in load_backend
    return import_module('%s.base' % backend_name)
  File "D:Program FilesPython3.6libimportlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "D:Program FilesPython3.6libsite-packagesdjangodbackendsmysqlase.py", line 21, in <module>
    ) from err
django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module.
Did you install mysqlclient?

解决方案

1、在 Python3.6Libsite-packagesdjangodbackendsmysqlase.py 中 加入以下两行

import pymysql
pymysql.install_as_MySQLdb()

2、再在项目中的init.py 中添加两行

import pymysql
pymysql.install_as_MySQLdb()

3、执行发现 还是报错

Traceback (most recent call last):
  File "manage.py", line 21, in <module>
    main()
  File "manage.py", line 17, in main
    execute_from_command_line(sys.argv)
  File "D:Program FilesPython3.6libsite-packagesdjangocoremanagement\__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "D:Program FilesPython3.6libsite-packagesdjangocoremanagement\__init__.py", line 377, in execute
    django.setup()
  File "D:Program FilesPython3.6libsite-packagesdjango\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "D:Program FilesPython3.6libsite-packagesdjangoapps
egistry.py", line 114, in populate
    app_config.import_models()
  File "D:Program FilesPython3.6libsite-packagesdjangoappsconfig.py", line 211, in import_models
    self.models_module = import_module(models_module_name)
  File "D:Program FilesPython3.6libimportlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 978, in _gcd_import
  File "<frozen importlib._bootstrap>", line 961, in _find_and_load
  File "<frozen importlib._bootstrap>", line 950, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 655, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 678, in exec_module
  File "<frozen importlib._bootstrap>", line 205, in _call_with_frames_removed
  File "D:Program FilesPython3.6libsite-packagesdjangocontribauthmodels.py", line 2, in <module>
    from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager
  File "D:Program FilesPython3.6libsite-packagesdjangocontribauthase_user.py", line 47, in <module>
    class AbstractBaseUser(models.Model):
  File "D:Program FilesPython3.6libsite-packagesdjangodbmodelsase.py", line 121, in __new__
    new_class.add_to_class('_meta', Options(meta, app_label))
  File "D:Program FilesPython3.6libsite-packagesdjangodbmodelsase.py", line 325, in add_to_class
    value.contribute_to_class(cls, name)
  File "D:Program FilesPython3.6libsite-packagesdjangodbmodelsoptions.py", line 208, in contribute_to_class
    self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
  File "D:Program FilesPython3.6libsite-packagesdjangodb\__init__.py", line 28, in __getattr__
    return getattr(connections[DEFAULT_DB_ALIAS], item)
  File "D:Program FilesPython3.6libsite-packagesdjangodbutils.py", line 207, in __getitem__
    backend = load_backend(db['ENGINE'])
  File "D:Program FilesPython3.6libsite-packagesdjangodbutils.py", line 111, in load_backend
    return import_module('%s.base' % backend_name)
  File "D:Program FilesPython3.6libimportlib\__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "D:Program FilesPython3.6libsite-packagesdjangodbackendsmysqlase.py", line 38, in <module>
    raise ImproperlyConfigured('mysqlclient 1.3.13 or newer is required; you have %s.' % Database.__version__)
django.core.exceptions.ImproperlyConfigured: mysqlclient 1.3.13 or newer is required; you have 0.8.1.

4、接着再修改 Python3.6Libsite-packagesdjangodbackendsmysqlase.py 

将以下两行就行注释

#注释掉 base.py 中如下部分（35/36行）
if version < (1, 3, 3):
     raise ImproperlyConfigured("mysqlclient 1.3.3 or newer is required; you have %s" % Database.__version__)

 再次执行发行创建成功

有的博文，说还有如下报错 ，以及后续的解决办法，但是本人没有遇到，顾未做修改

AttributeError: ‘str’ object has no attribute ‘decode’

#找到operations.py文件（46行,版本不同行数不同哈~自个儿find一下），将decode改为encode
#linux vim 查找快捷键：？decode
if query is not None:
    query = query.decode(errors='replace')
return query
#改为
if query is not None:
    query = query.encode(errors='replace')
return query
————————————————

原文链接：https://blog.csdn.net/weixin_33127753/java/article/details/89100552

解决原理

Django连接MySQL时默认使用MySQLdb驱动，但MySQLdb不支持Python3，因此这里将MySQL驱动设置为pymysql