python - Creating database with SQLAlchemy in Flask -

i'd know, need create sqlalchemy database in flask. according documentation should create model in flask app , go python shell , create using db.create_all(). doesn't work.

my flask app:

import os import flask import settings 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:

>>> 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     self._optional_conn_ctx_manager(connection) 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     self.contextual_connect() 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 open database file  none none 

you have 1 many / in database uri. format dialect+driver://user:pass@host:port/db_name. sqlite, db_name path database. you've specified absolute path /database.db, means you're trying create database in filesystem's root directory.

using sqlite:///database.db (a relative path) create database in (relative to) current working directory.

you want specify absolute path, build based on project location, since run application folder. assuming want create db in same directory app setup code, build path relative __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