Flask SQLAlchemy连接到MySQL数据库

Question

Setup & Code:

I'm building a basic Flask Application with an an AngularJS front end and I am currently at the point where I need to make a connection to a MySQL database I have hosted with Godaddy phpmyadmin.

This is part of my __init__.py

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

# Create instnace called app
app = Flask(__name__)
app.config['SQLAlchemy_DATABASE_URI'] = 'mysql://username:password#@xxxxxx.hostedresource.com/dbname'

# Create SQLAlchemy object
db = SQLAlchemy(app)
# ...

This is my models.py

from app import app, db

class UsersPy(db.Model):

  __tablename__ = "userspy"

  id = db.Column(db.Integer, primary_key=True)
  username = db.Column(db.String, nullable=False)
  password = db.Column(db.String, nullable=False)

  def __init__(self, username, password):
    self.username = username
    self.password = password

  def __repr__(self):
    return '<title {}'.format(self.username)

This is a snippet from my views.py:

from app import app, db
from app.models import UsersPy
from flask import render_template, request, redirect, url_for, jsonify, session, flash

@app.route('/testdb/')
def testdb():
    admin = UsersPy('user1', 'password1')
    guest = UsersPy('user2', 'password2')

    db.session.add(admin)
    db.session.add(guest)

    #db.session.merge(admin)
    #db.session.merge(guest)
    db.session.commit()

    results = UsersPy.query.all()

    json_results = []
    for result in results:
      d = {'username': result.username,
           'password': result.password}
      json_results.append(d)

    return jsonify(items=json_results)

Problem:

All of this works well, the users are 'created' and displayed back in JSON format when you visit the /testdb/ location, however the actual database hosted with Godaddy is not being updated so the real connection must not be being made or it is failing for some reason. I have the userspy database table already created but add() and commit() functions are not actually adding users to the database. I can't figure out how to solidify the connection between SQLAlchemy and the MySQL Database. Any help is appreciated, thanks.

Answer 1

A good first step in debugging this would be to set SQLALCHEMY_ECHO to True in your app configuration. This will cause the actual MySQL database statements that SQLAlchemy is executing to be printed out.

Also, it's worth noting that SQLAlchemy_DATABASE_URI is different from SQLALCHEMY_DATABASE_URI , which is what the Flask-SQLAlchemy documentation states the config key should be.