ORM

Object-Relational Mapping is implemented using Flask-SQLAlchemy.

Defining and mapping models

First off you need to define your models as described by the SQL-Alchemy documentation:

# app/database/models/users.py
from edmunds.database.db import db
class User(db.Model):
    # __bind_key__ = 'users_database'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(50))

# app/database/models/tags.py
from edmunds.database.db import db
class Tag(db.Model):
    # __bind_key__ = 'users_database'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(50), unique=True)

# app/database/models/usertags.py
from edmunds.database.db import db
UserTagsTable = db.Table(
    'user_tags',
    db.Column('user_id', db.Integer, db.ForeignKey('tags.id'), primary_key=True),
    db.Column('tag_id', db.Integer, db.ForeignKey('users.id'), primary_key=True),
    # info={'bind_key': 'users_database'}
)

Insert, Update, Delete

The actions work the same way as Flask-SQLAlchemy does:

session = app.database_session()
peter = User(name='peter')

# Inserting
session.add(peter)
session.commit()
print peter.id

# Updating
peter.name = 'peter verkest'
session.commit()

# Deleting
session.delete(peter)
session.commit()

Further documentation:

• Flask-SQLAlchemy Select, Insert, Delete
• SQLAlchemy Adding and Updating Objects

Note: These actions are handy, but not efficient when running in bulk. Take a look at this StackOverflow-question.

Querying

Querying works as defined in Flask-SQLAlchemy.

users = User.query.all()
peter = User.query.filter_by(name='peter').first()

Further documentation on querying:

• Flask-SQLAlchemy Querying Records
• SQLAlchemy Querying