Creating a database in flask sqlalchemy

flask, flask-sqlalchemy, python

Solution

You either have to create a request or you have to create the models with sqlalchemy directly. We do something similar at work and chose the former.

Flask lets you create a test request to initialize an app. Try something like

from application.database import db
from application.server import app

with app.test_request_context():
     db.init_app(app)

     db.create_all()

Problem

I'm building a Flask app with Flask-SQLAlchemy and I'm trying to write a script that will create a Sqlite3 database without running the main application. In order to avoid circular references, I've initialized the main Flask app object and the SQLAlchemy database object in separate modules. I then import and combine them in a third file when running the app. This works fine when I'm running the app, as the database is built and operates properly when create rows and query them. However, when I try to import them in another module, I get the following error: ``` RuntimeError: application not registered on db instance and no applicationbound to current context ``` My code looks like the following: root/create_database.py ``` from application.database import db from application.server import app db.init_app(app) db.create_all() ``` root/run.sh ``` export FLASK_APP=application/server.py flask run ``` root/application/init.py ``` from database import db from server import app db.init_app(app) from routes import apply_routes apply_routes(app) ``` root/application/database.py ``` from flask_sqlalchemy import SQLAlchemy db = SQLAlchemy() ``` root/application/server.py ``` from flask import Flask import os app = Flask(__name__) path = os.path.dirname( os.path.realpath(__file__) ) database_path = os.path.join(path, '../mydb.sqlite') app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///' + database_path ``` root/application/models/init.py ``` from user import User ``` root/application/models/user.py ``` from application.database import db class User(db.Model): id = db.Column(db.Integer, primary_key=True) username = db.Column(db.String(80), unique=True) password = db.Column(db.String(120)) def __init__(self, username, password): self.username = username self.password = password ``` In my create_database.py script I'm trying to make sure that the SQLAlchemy `db` instance is configured with the config details from the `app` object, but it doesn't seem to be connecting for some reason. Am I missing something important here?

Original source