我正在尝试使用Flask-SQLAlchemy并遇到了一些问题。请看一下我正在使用的两个文件。当我运行gwg.py
并转到/util/db/create-all
时,它会输出一个错误没有这样的表:stories
。我认为我做的一切都正确;有人可以指出我错过了什么或者出了什么问题吗?它确实创建了data.db文件,但该文件显示为0Kb。
gwg.py:
application = Flask(__name__)
db = SQLAlchemy(application)
import models
# Utility
util = Blueprint('util', __name__, url_prefix='/util')
@util.route('/db/create-all/')
def db_create_all():
db.create_all()
return 'Tables created'
application.register_blueprint(util)
application.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///data.db'
application.debug = True
application.run()
models.py:
from gwg import application, db
class Story(db.Model):
__tablename__ = 'stories'
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(150))
subscribed = db.Column(db.Boolean)
def __init__(self, name):
self.name = name
self.subscribed = False
def toggle_subscription(self):
self.subscribed = False if self.subscribed else True
编辑
以下是似乎触发错误的函数,但不应该如此,因为我明确先转到 /util/db/create-all 然后重新加载/。即使在出现错误之后,我也会前往 /util/db/create-all,然后前往 /,但仍然会收到相同的错误提示。
@application.route('/')
def homepage():
stories = models.Story.query.all()
return render_template('index.html', stories=stories)
堆栈跟踪
sqlalchemy.exc.OperationalError
OperationalError: (OperationalError) no such table: stories u'SELECT stories.id AS stories_id, stories.name AS stories_name, stories.subscribed AS stories_subscribed \nFROM stories' ()
Traceback (most recent call last)
File "C:\Python27\lib\site-packages\flask\app.py", line 1836, in __call__
return self.wsgi_app(environ, start_response)
File "C:\Python27\lib\site-packages\flask\app.py", line 1820, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "C:\Python27\lib\site-packages\flask\app.py", line 1403, in handle_exception
reraise(exc_type, exc_value, tb)
File "C:\Python27\lib\site-packages\flask\app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "C:\Python27\lib\site-packages\flask\app.py", line 1477, in full_dispatch_request
rv = self.handle_user_exception(e)
File "C:\Python27\lib\site-packages\flask\app.py", line 1381, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "C:\Python27\lib\site-packages\flask\app.py", line 1475, in full_dispatch_request
rv = self.dispatch_request()
File "C:\Python27\lib\site-packages\flask\app.py", line 1461, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "C:\Users\kylee\Code\GWG\gwg.py", line 20, in homepage
stories = models.Story.query.all()
File "C:\Python27\lib\site-packages\sqlalchemy\orm\query.py", line 2104, in all
return list(self)
File "C:\Python27\lib\site-packages\sqlalchemy\orm\query.py", line 2216, in __iter__
return self._execute_and_instances(context)
File "C:\Python27\lib\site-packages\sqlalchemy\orm\query.py", line 2231, in _execute_and_instances
result = conn.execute(querycontext.statement, self._params)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 662, in execute
params)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 761, in _execute_clauseelement
compiled_sql, distilled_params
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 874, in _execute_context
context)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 1024, in _handle_dbapi_exception
exc_info
File "C:\Python27\lib\site-packages\sqlalchemy\util\compat.py", line 163, in raise_from_cause
reraise(type(exception), exception, tb=exc_tb)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 867, in _execute_context
context)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\default.py", line 324, in do_execute
cursor.execute(statement, parameters)
OperationalError: (OperationalError) no such table: stories u'SELECT stories.id AS stories_id, stories.name AS stories_name, stories.subscribed AS stories_subscribed \nFROM stories' ()
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/util/db/create-all
是出错了还是成功了(返回“Tables created”),但你的 SQLite 文件是空的? - Mark Hildrethdata.db
,但该文件为空。当我返回localhost/时,就会出现堆栈跟踪错误,指出不存在任何表。我认为我的实现与Flask-SQLAlchemy在其文档中给出的示例非常接近。 - user2545155