Questions about using Flask+MySQL+Flask-SQLAlchemy - mysql

Question

I am going to build a site using Flask+MySQL+Flask-SQLAlchemy, however, after reading some tutorials, I have some questions:
Flask-SQLAlchemy can be imported in at least two ways:
http://pythonhosted.org/Flask-SQLAlchemy/quickstart.html
from flask.ext.sqlalchemy import SQLAlchemy
OR http://flask.pocoo.org/docs/patterns/sqlalchemy/
from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session, sessionmaker
from sqlalchemy.ext.declarative import declarative_base
The first way seems much more convenient. Why Pocoo team choose to use the second way?
http://pythonhosted.org/Flask-SQLAlchemy/queries.html The insert examples here are too simple. How can I perform INSERT
IGNORE or INNER JOIN? If I want to write native SQL statements. How to do that with SQLAlchemy?
I need some good examples on MySQL+Flask-SQLAlchemy, while most example are SQLite+MySQL+Flask-SQLAlchemy.

Answer 1

I have been coding using MySQL+Flask-SQLAlchemy and i host my applications on pythonanywhere.com ,like what #Sean Vieira said ,your code will run on any Relational database the only thing you need to change is the connection string to the database of your liking ,e.g using Mysql ,this will be saved in a file called config.py [you can save it using any other name]
SQLALCHEMY_DATABASE_URI = 'mysql://username:password#localhost/yourdatabase'
SQLALCHEMY_POOL_RECYCLE = 280
SQLALCHEMY_POOL_SIZE = 20
SQLALCHEMY_TRACK_MODIFICATIONS = True
then in your main app ,you will import it like this
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
# Create an Instance of Flask
application = Flask(__name__)
# Include config from config.py
application.config.from_object('config')
application.secret_key = 'some_secret_key'
# Create an instance of SQLAlchemy
db = SQLAlchemy(application)
and all you need is to make sure your models correspond to a database table like the model below
class Isps(db.Model):
__tablename__ = "isps"
isp_id = db.Column('isp_id', db.Integer, primary_key=True)
isp_name = db.Column('isp_name', db.String(80), unique=True)
isp_description = db.Column('isp_description', db.String(180))
# services = db.relationship('Services', backref="isps", cascade="all, delete-orphan",lazy='dynamic')
def __init__(self, isp_name, isp_description):
self.isp_name = isp_name
self.isp_description = isp_description
def __repr__(self):
return '<Isps %r>' % self.isp_name
and you can then learn the power of SQLAlchemy to do optimised queries

Answer 2

Flask-SQLAlchemy was written by Armin (the creator of Flask) to make it simple to work with SQLAlchemy. The pattern described in Flask's documentation is what you would use if you did not choose to use the Flask-SQLAlchemy extension.
As for MySQL vs. SQLite, the whole point of the SQLAlchemy ORM is to make it possible (for the most part) to ignore what database you are running against. SomeModel.filter(SomeModel.column == 'value') will work the same, regardless of what database you are connecting to.