在Python 2 Django应用中，我定义了一个带有'money with wings'表情符号的字符串：
# -*- coding: UTF-8 -*-
MESSAGE = "Stash some cash "
这将使pylint棉短罚款通过。
但是，我也有一个带有Message字段的模型content，如果我尝试在其中写入内容，则会收到错误消息：
Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8mb4_general_ci,COERCIBLE) for operation '='
下面是完整的堆栈跟踪。我怎样才能解决这个问题？由于utf8mb4_general_ci是特定于MySQL的，因此我假设数据库当前处于编码状态，而utf8_general_ci是我正在定义字符串的编码。如何定义我的字符串在utf8mb4_general_ci中而不是utf8_general_ci中？
/app/venmo_platform/current/venmo/communication/services/notification_service.pyc in get_message_for_notification(message_content)
99
100 def get_message_for_notification(message_content):
--> 101 message, _ = Message.objects.get_or_create(content=message_content)
102 return message
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/django/db/models/manager.pyc in manager_method(self, *args, **kwargs)
125 def create_method(name, method):
126 def manager_method(self, *args, **kwargs):
--> 127 return getattr(self.get_queryset(), name)(*args, **kwargs)
128 manager_method.__name__ = method.__name__
129 manager_method.__doc__ = method.__doc__
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/django/db/models/query.pyc in get_or_create(self, defaults, **kwargs)
403 self._for_write = True
404 try:
--> 405 return self.get(**lookup), False
406 except self.model.DoesNotExist:
407 return self._create_object_from_params(lookup, params)
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/django/db/models/query.pyc in get(self, *args, **kwargs)
326 if self.query.can_filter():
327 clone = clone.order_by()
--> 328 num = len(clone)
329 if num == 1:
330 return clone._result_cache[0]
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/django/db/models/query.pyc in __len__(self)
142
143 def __len__(self):
--> 144 self._fetch_all()
145 return len(self._result_cache)
146
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/django/db/models/query.pyc in _fetch_all(self)
963 def _fetch_all(self):
964 if self._result_cache is None:
--> 965 self._result_cache = list(self.iterator())
966 if self._prefetch_related_lookups and not self._prefetch_done:
967 self._prefetch_related_objects()
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/django/db/models/query.pyc in iterator(self)
236 # Execute the query. This will also fill compiler.select, klass_info,
237 # and annotations.
--> 238 results = compiler.execute_sql()
239 select, klass_info, annotation_col_map = (compiler.select, compiler.klass_info,
240 compiler.annotation_col_map)
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/django/db/models/sql/compiler.pyc in execute_sql(self, result_type)
838 cursor = self.connection.cursor()
839 try:
--> 840 cursor.execute(sql, params)
841 except Exception:
842 cursor.close()
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/django/db/backends/utils.pyc in execute(self, sql, params)
77 start = time()
78 try:
---> 79 return super(CursorDebugWrapper, self).execute(sql, params)
80 finally:
81 stop = time()
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/django/db/backends/utils.pyc in execute(self, sql, params)
62 return self.cursor.execute(sql)
63 else:
---> 64 return self.cursor.execute(sql, params)
65
66 def executemany(self, sql, param_list):
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/django/db/utils.pyc in __exit__(self, exc_type, exc_value, traceback)
96 if dj_exc_type not in (DataError, IntegrityError):
97 self.wrapper.errors_occurred = True
---> 98 six.reraise(dj_exc_type, dj_exc_value, traceback)
99
100 def __call__(self, func):
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/django/db/backends/utils.pyc in execute(self, sql, params)
62 return self.cursor.execute(sql)
63 else:
---> 64 return self.cursor.execute(sql, params)
65
66 def executemany(self, sql, param_list):
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/django/db/backends/mysql/base.pyc in execute(self, query, args)
122 try:
123 # args is None means no string interpolation
--> 124 return self.cursor.execute(query, args)
125 except Database.OperationalError as e:
126 # Map some error codes to IntegrityError, since they seem to be
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/MySQLdb/cursors.pyc in execute(self, query, args)
248 except Exception:
249 exc, value = sys.exc_info()[:2]
--> 250 self.errorhandler(self, exc, value)
251 self._executed = query
252 if not self._defer_warnings:
/app/shared/virtualenvs/venmo_platform27/local/lib/python2.7/site-packages/MySQLdb/connections.pyc in defaulterrorhandler(***failed resolving arguments***)
48 del connection
49 if isinstance(errorvalue, BaseException):
---> 50 raise errorvalue
51 if errorclass is not None:
52 raise errorclass(errorvalue)
OperationalError: (1267, "Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8mb4_general_ci,COERCIBLE) for operation '='")