無法在瓶子應用程序中創建sqlite3數據庫？

Question

我有以下腳本：

#!flask/bin/python 
import os 

from flask import Flask, render_template, request, url_for 
from flask.ext.sqlalchemy import SQLAlchemy 

app = Flask("hello") 

basedir = os.path.abspath(os.path.dirname(__file__)) 
SQLALCHEMY_DATABASE_URI = 'sqlite:///' + os.path.join(basedir, 'app.sqlite3') 
print SQLALCHEMY_DATABASE_URI 
db = SQLAlchemy(app) 

db.create_all() 

print db 

但是當我實際運行該腳本，我沒有看到任何東西：

$ python db_create.py 
sqlite:////home/ubuntu/Paw/paw/app.sqlite3 
/home/ubuntu/.virtualenvs/paw-py/local/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py:800: UserWarning: SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future. Set it to True to suppress this warning. 
    warnings.warn('SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future. Set it to True to suppress this warning.') 
<SQLAlchemy engine='sqlite://'> 

那麼，爲什麼我看到被放置在內存中的SQLAlchemy的發動機？

我的權限似乎也不錯。

Answer 1

您所做的全部事情都是創建一個名爲SQLALCHEMY_DATABASE_URI的變量。您沒有做任何事情來告訴SQLAlchemy使用該值。

如the docs所示，你需要將它傳遞給app.config：

app = Flask(__name__) 
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + os.path.join(basedir, 'app.sqlite3') 
db = SQLAlchemy(app)