I'd like to know, what I need to do to create SQLAlchemy database in Flask. According to documentation I should create model in my Flask app and then go to the Python shell and just create this by using db.create_all(). But that doesn't work.
My Flask app:
import os
import flask
import settings
from flask_sqlalchemy import SQLAlchemy
app = flask.Flask(__name__)
app.config['SESSION_TYPE'] = 'filesystem'
app.secret_key = os.urandom(24)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:////database.db'
db = SQLAlchemy(app)
(...)
Model:
from app import db
class User(db.Model):
id = db.Column(db.Integer, primary_key = True)
username = db.Column(db.String(15), unique = True)
password = db.Column(db.String(15), unique = True)
tasks = db.relationship('Task', backref='author', lazy='dynamic')
def __init__(self, username, password):
self.username = username
self.password = password
class Task(db.Model):
id = db.Column(db.Integer, primary_key = True)
scene = db.Column(db.String(140), nullable = False)
state = db.Column(db.Integer(1), nullable = False)
progress = db.Column(db.Integer(3), nullable = False)
add_date = db.Column(db.DateTime, nullable = False)
start_date = db.Column(db.DateTime, nullable = False)
finish_date = db.Column(db.DateTime, nullable = False)
rendered_scene = db.Column(db.String(140))
user_id = db.Column(db.Integer, db.ForeignKey('user.id'))
Error code:
>>> from app import db
>>> db.create_all()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Python27\lib\site-packages\flask_sqlalchemy\__init__.py", line 895, in create_all
self._execute_for_all_tables(app, bind, 'create_all')
File "C:\Python27\lib\site-packages\flask_sqlalchemy\__init__.py", line 887, in _execute_for_all_tables
op(bind=self.get_engine(app, bind), **extra)
File "C:\Python27\lib\site-packages\sqlalchemy\sql\schema.py", line 3420, in create_all
tables=tables)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 1727, in_run_visitor
with self._optional_conn_ctx_manager(connection) as conn:
File "C:\Python27\lib\contextlib.py", line 17, in __enter__
return self.gen.next()
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 1720, in_optional_conn_ctx_manager
with self.contextual_connect() as conn:
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 1910, incontextual_connect
self.pool.connect(),
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 338, in connect
return _ConnectionFairy._checkout(self)
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 645, in _checkout
fairy = _ConnectionRecord.checkout(pool)
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 440, in checkout
rec = pool._do_get()
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 1058, in _do_get
return self._create_connection()
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 285, in _create_connection
return _ConnectionRecord(self)
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 411, in __init__
self.connection = self.__connect()
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 539, in __connect
connection = self.__pool._creator()
File "C:\Python27\lib\site-packages\sqlalchemy\engine\strategies.py", line 96, in connect
connection_invalidated=invalidated
File "C:\Python27\lib\site-packages\sqlalchemy\util\compat.py", line 199, in raise_from_cause
reraise(type(exception), exception, tb=exc_tb)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\strategies.py", line 90, in connect
return dialect.connect(*cargs, **cparams)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\default.py", line 377, in connect
return self.dbapi.connect(*cargs, **cparams)
sqlalchemy.exc.OperationalError: (OperationalError) unable to open database file
None None
You have one too many / in the database uri. The format is dialect+driver://user:pass@host:port/db_name. With SQLite, db_name is the path to the database. You've specified the absolute path /database.db, which means you're trying to create the database in the filesystem's root directory.
Using sqlite:///database.db (a relative path) will create the database in (relative to) the current working directory.
You probably want to specify an absolute path, but build it based on the project location, since you could run the application from another folder. Assuming you want to create the db in the same directory as the app setup code, build a path relative to __file__.
db_path = os.path.join(os.path.dirname(__file__), 'app.db')
db_uri = 'sqlite:///{}'.format(db_path)
app.config['SQLALCHEMY_DATABASE_URI'] = db_uri
Collected from the Internet
Please contact [email protected] to delete if infringement.
Comments