Heroku应用因数据库崩溃

Question

我的代码在本地运行没问题，但在Heroku上运行就不行。我在Heroku上添加了数据库，但还是不行。有没有人知道为什么会这样？

import sys
import os

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

db_local =   #it works, just not shown here

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = os.environ.get('DATABASE_URL', db_local)

app.secret_key = '  '  #it's a secret for a reason

db = SQLAlchemy(app)

from views import *
from model import *
db.create_all()

if __name__ == '__main__':
    port = int(os.environ.get('PORT', 5000))
    app.run(host='0.0.0.0', port=port, debug=True)

这是我一些Heroku的日志

2013-02-19T22:29:59+00:00 app[web.1]:   File "app.py", line 23, in <module>
2013-02-19T22:29:59+00:00 app[web.1]:     from views import *
2013-02-19T22:29:59+00:00 app[web.1]:   File "/app/views.py", line 1, in <module>
2013-02-19T22:29:59+00:00 app[web.1]:     from app import db
2013-02-19T22:29:59+00:00 app[web.1]:   File "/app/app.py", line 25, in <module>
2013-02-19T22:29:59+00:00 app[web.1]:     db.create_all()
2013-02-19T22:29:59+00:00 app[web.1]:     self._execute_for_all_tables(app, bind, 'create_all')
2013-02-19T22:29:59+00:00 app[web.1]:   File "/app/.heroku/python/lib/python2.7/site-packages/flask_sqlalchemy.py", line 822, in create_all
2013-02-19T22:29:59+00:00 app[web.1]:   File "/app/.heroku/python/lib/python2.7/site-packages/flask_sqlalchemy.py", line 814, in _execute_for_all_tables
2013-02-19T22:29:59+00:00 app[web.1]:   File "/app/.heroku/python/lib/python2.7/site-packages/sqlalchemy/schema.py", line 2564, in create_all
2013-02-19T22:29:59+00:00 app[web.1]:     import utils
2013-02-19T22:29:59+00:00 app[web.1]:   File "/app/utils.py", line 1, in <module>
2013-02-19T22:29:59+00:00 app[web.1]: Traceback (most recent call last):
2013-02-19T22:29:59+00:00 app[web.1]:     conn = self.contextual_connect(close_with_result=False)
2013-02-19T22:29:59+00:00 app[web.1]:   File "/app/.heroku/python/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 2490, in contextual_connect
2013-02-19T22:29:59+00:00 app[web.1]:     self.pool.connect(), 
2013-02-19T22:29:59+00:00 app[web.1]:     tables=tables)
2013-02-19T22:29:59+00:00 app[web.1]:     con = self._create_connection()

Answer 1

我想你的配置变量中可能没有DATABASE_URL这个值。你可以通过运行heroku config:get DATABASE_URL --app your-app来确认一下。

你可以试试heroku pg:info --app your-app来查看你安装了哪些数据库。确保你的数据库也被设置为DATABASE_URL（在pg:info的输出中也会显示出来）。如果没有的话，只需运行heroku pg:promote HEROKU_POSTGRESQL_<color> --app your-app，然后再试试你的脚本。