我正在将项目的Django版本从1.11更新到django 2.0.8。当我运行从LiveServerTestCase继承并得到此错误的测试时，说：
sqlite3.OperationalError：数据库表已锁定
在StaticLiverServerTestCase上获得了相同的错误。
跟踪：
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/django/core/handlers/exception.py", line 35, in inner
response = get_response(request)
File "/usr/local/lib/python3.6/site-packages/django/core/handlers/base.py", line 128, in _get_response
response = self.process_exception_by_middleware(e, request)
File "/usr/local/lib/python3.6/site-packages/django/core/handlers/base.py", line 126, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/usr/local/lib/python3.6/site-packages/django/views/decorators/csrf.py", line 54, in wrapped_view
return view_func(*args, **kwargs)
File "/usr/local/lib/python3.6/site-packages/rest_framework/viewsets.py", line 103, in view
return self.dispatch(request, *args, **kwargs)
File "/usr/local/lib/python3.6/site-packages/django/utils/decorators.py", line 62, in _wrapper
return bound_func(*args, **kwargs)
File "/usr/local/lib/python3.6/site-packages/django/utils/decorators.py", line 142, in _wrapped_view
response = view_func(request, *args, **kwargs)
File "/usr/local/lib/python3.6/site-packages/django/utils/decorators.py", line 58, in bound_func
return func.__get__(self, type(self))(*args2, **kwargs2)
File "/pipeline/source/core/api_views.py", line 21, in dispatch
return super(CurrencyViewSet, self).dispatch(*args, **kwargs)
File "/usr/local/lib/python3.6/site-packages/rest_framework/views.py", line 483, in dispatch
response = self.handle_exception(exc)
File "/usr/local/lib/python3.6/site-packages/rest_framework/views.py", line 443, in handle_exception
self.raise_uncaught_exception(exc)
File "/usr/local/lib/python3.6/site-packages/rest_framework/views.py", line 480, in dispatch
response = handler(request, *args, **kwargs)
File "/usr/local/lib/python3.6/site-packages/rest_framework/mixins.py", line 48, in list
return Response(serializer.data)
File "/usr/local/lib/python3.6/site-packages/rest_framework/serializers.py", line 765, in data
ret = super(ListSerializer, self).data
File "/usr/local/lib/python3.6/site-packages/rest_framework/serializers.py", line 262, in data
self._data = self.to_representation(self.instance)
File "/usr/local/lib/python3.6/site-packages/rest_framework/serializers.py", line 683, in to_representation
self.child.to_representation(item) for item in iterable
File "/usr/local/lib/python3.6/site-packages/django/db/models/query.py", line 272, in __iter__
self._fetch_all()
File "/usr/local/lib/python3.6/site-packages/django/db/models/query.py", line 1179, in _fetch_all
self._result_cache = list(self._iterable_class(self))
File "/usr/local/lib/python3.6/site-packages/django/db/models/query.py", line 53, in __iter__
results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
File "/usr/local/lib/python3.6/site-packages/django/db/models/sql/compiler.py", line 1068, in execute_sql
cursor.execute(sql, params)
File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py", line 68, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py", line 77, in _execute_with_wrappers
return executor(sql, params, many, context)
File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py", line 85, in _execute
return self.cursor.execute(sql, params)
File "/usr/local/lib/python3.6/site-packages/django/db/utils.py", line 89, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "/usr/local/lib/python3.6/site-packages/django/db/backends/utils.py", line 85, in _execute
return self.cursor.execute(sql, params)
File "/usr/local/lib/python3.6/site-packages/django/db/backends/sqlite3/base.py", line 303, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: database table is locked
什么会导致此问题？感谢您的任何帮助，谢谢！