Database

Database usage is built in in Edmunds and uses Flask-SQLAlchemy.

Settings

You can set your database preferences in the settings:

from edmunds.database.drivers.mysql import MySql
from edmunds.database.drivers.postgresql import PostgreSql
from edmunds.database.drivers.sqlite import Sqlite

APP = {
    'database':
    {
        'enabled': True,
        'instances':
        [
            {
                'name': 'mysql',
                'driver': MySql,
                'user': 'root',
                'pass': 'root',
                'host': 'localhost',
                'database': 'edmunds',
                # 'port': '3306',   # Optional, default: '3306'
            },
            {
                'name': 'postgresql',
                'driver': PostgreSql,
                'user': 'root',
                'pass': 'root',
                'host': 'localhost',
                'database': 'edmunds',
                # 'port': '5432',   # Optional, default: '5432'
            },
            {
                'name': 'sqlite',
                'driver': Sqlite,
                'file': '/database/sqlite.db',
                # 'storage': 'storage_name',    # Optional, default storage used as default
            },
        ],
    },
}

The instances can be used for database, so you can have multiple at once. The first one will be used by default.

The available drivers are:

MySql: For MySQL databases.
PostgreSql: For PostgreSQL databases.
SQLite: For SQLite databases.

More in detail: the default instance will be used as SQLALCHEMY_DATABASE_URI in SQLAlchemy. Other instances (not including the default instance) will be added to SQLALCHEMY_BINDS.

Usage

When fetching an instance, you will receive a database-engine (sqlalchemy.engine.base.Engine) for the specified database instance. You can request one like so:

# Fetch the default driver, or by name
engine = app.database_engine()
engine = app.database_engine(name='mysql')

Fetching a session can be done with database_session. You will receive a Session-class (sqlalchemy.orm.scoping.scoped_session) for session-usage. Sessions will be teared down when the request ends or when the app shuts down (using app.teardown_appcontext).

session = app.database_session()
session = app.database_session(name='mysql')

session.add(user)
session.commit()

Further usage of the database-engine and -session are described in the SQLAlchemy documentation: