第一次点进去的时候出错了

Traceback (most recent call last):
File "/usr/local/sae/python/lib/python2.7/site-packages/sae/__init__.py", line 18, in new_app
return app(environ, start_response)
File "/usr/local/sae/python/lib/python2.7/site-packages/flask/app.py", line 1306, in __call__
return self.wsgi_app(environ, start_response)
File "/usr/local/sae/python/lib/python2.7/site-packages/flask/app.py", line 1294, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/usr/local/sae/python/lib/python2.7/site-packages/flask/app.py", line 1292, in wsgi_app
response = self.full_dispatch_request()
File "/usr/local/sae/python/lib/python2.7/site-packages/flask/app.py", line 1062, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/usr/local/sae/python/lib/python2.7/site-packages/flask/app.py", line 1060, in full_dispatch_request
rv = self.dispatch_request()
File "/usr/local/sae/python/lib/python2.7/site-packages/flask/app.py", line 1047, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/data1/www/htdocs/634/rebang/1/chartnet/view/views.py", line 190, in detailpost
_article = operatorDB.detail_post_by_id(post_id)
File "/data1/www/htdocs/634/rebang/1/chartnet/view/models.py", line 330, in detail_post_by_id
article = Article.query.filter_by(_id=_id).first()
File "/usr/local/sae/python/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 1963, in first
ret = list(self[0:1])
File "/usr/local/sae/python/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 1857, in __getitem__
return list(res)
File "/usr/local/sae/python/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2032, in __iter__
return self._execute_and_instances(context)
File "/usr/local/sae/python/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2045, in _execute_and_instances
close_with_result=True)
File "/usr/local/sae/python/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2036, in _connection_from_session
**kw)
File "/usr/local/sae/python/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 719, in connection
close_with_result=close_with_result)
File "/usr/local/sae/python/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 723, in _connection_for_bind
return self.transaction._connection_for_bind(engine)
File "/usr/local/sae/python/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 249, in _connection_for_bind
self._assert_is_active()
File "/usr/local/sae/python/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 177, in _assert_is_active
"This Session's transaction has been rolled back "
InvalidRequestError: This Session's transaction has been rolled back by a nested rollback() call. To begin a new transaction, issue Session.rollback() first.