Our first model

You may have noted that we did not actually create any tables in our database to abstract off of. This is because SQLAlchemy allows us to create either models from tables or tables from our models. This will be covered after we create the first model.

In our main.py file, SQLAlchemy must first be initialized with our app as follows:

from flask.ext.sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config.from_object(DevConfig)
db = SQLAlchemy(app)

SQLAlchemy will read our app's configuration and automatically connect to our database. Let's create a User model to interact with a user table in the main.py file:

class User(db.Model):
    id = db.Column(db.Integer(), primary_key=True)
    username = db.Column(db.String(255))
    password = db.Column(db.String(255))

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

    def __repr__(self):
        return "<User '{}'>".format(self.username)

What have we accomplished? We now have a model that is based on...