How to Migrate SQLAlchemy Databases for Flask Applications

Flask-Migrate

Flask-Migrate is an extension that handles SQLAlchemy database migrations for Flask applications using Alembic. The database operations are provided as command-line arguments under the flask db command.

Installation

Install Flask-Migrate with pip:

pip install Flask-Migrate

Example

This is an example application that handles database migrations through Flask-Migrate:

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///app.db'

db = SQLAlchemy(app)
migrate = Migrate(app, db)

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(128))

With the above application you can create the database or enable migrations if the database already exists with the following command:

$ flask db init

Note that the FLASK_APP environment variable must be set according to the Flask documentation for this command to work. This will add a migrations folder to your application. The contents of this folder need to be added to version control along with your other source files.

You can then generate an initial migration:

$ flask db migrate

The migration script needs to be reviewed and edited, as Alembic currently does not detect every change you make to your models. In particular, Alembic is currently unable to detect indexes. Once finalized, the migration script also needs to be added to version control.

Then you can apply the migration to the database:

$ flask db upgrade

Then each time the database models change repeat the migrate and upgrade commands.

To sync the database in another system just refresh the migrations folder from source control and run the upgrade command.

To see all the commands that are available run this command:

$ flask db --help

---

Author: miguelgrinberg
Source Code: https://github.com/miguelgrinberg/Flask-Migrate
License: MIT License

#python #sqlalchemy #flask 

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Buddha Community

Django-allauth: A simple Boilerplate to Setup Authentication

Django-Authentication 

A simple Boilerplate to Setup Authentication using Django-allauth, with a custom template for login and registration using django-crispy-forms.

Getting Started

Prerequisites

• Python 3.8.6 or higher

Project setup

# clone the repo
$ git clone https://github.com/yezz123/Django-Authentication

# move to the project folder
$ cd Django-Authentication

Creating virtual environment

• Create a virtual environment for this project:

# creating pipenv environment for python 3
$ virtualenv venv

# activating the pipenv environment
$ cd venv/bin #windows environment you activate from Scripts folder

# if you have multiple python 3 versions installed then
$ source ./activate

Configured Enviromment

Environment variables

SECRET_KEY = #random string
DEBUG = #True or False
ALLOWED_HOSTS = #localhost
DATABASE_NAME = #database name (You can just use the default if you want to use SQLite)
DATABASE_USER = #database user for postgres
DATABASE_PASSWORD = #database password for postgres
DATABASE_HOST = #database host for postgres
DATABASE_PORT = #database port for postgres
ACCOUNT_EMAIL_VERIFICATION = #mandatory or optional
EMAIL_BACKEND = #email backend
EMAIL_HOST = #email host
EMAIL_HOST_PASSWORD = #email host password
EMAIL_USE_TLS = # if your email use tls
EMAIL_PORT = #email port

change all the environment variables in the .env.sample and don't forget to rename it to .env.

Run the project

After Setup the environment, you can run the project using the Makefile provided in the project folder.

help:
 @echo "Targets:"
 @echo "    make install" #install requirements
 @echo "    make makemigrations" #prepare migrations
 @echo "    make migrations" #migrate database
 @echo "    make createsuperuser" #create superuser
 @echo "    make run_server" #run the server
 @echo "    make lint" #lint the code using black
 @echo "    make test" #run the tests using Pytest

Preconfigured Packages

Includes preconfigured packages to kick start Django-Authentication by just setting appropriate configuration.

Package	Usage
django-allauth	Integrated set of Django applications addressing authentication, registration, account management as well as 3rd party (social) account authentication.
django-crispy-forms	django-crispy-forms provides you with a crispy filter and {% crispy %} tag that will let you control the rendering behavior of your Django forms in a very elegant and DRY way.

Contributing

• Django-Authentication is a simple project, so you can contribute to it by just adding your code to the project to improve it.
• If you have any questions, please feel free to open an issue or create a pull request.

Download Details:
Author: yezz123
Source Code: https://github.com/yezz123/Django-Authentication
License: MIT License

#django #python 

SQLAlchemy Database Migrations for Flask Applications using Alembic

Flask-Migrate

Flask-Migrate is an extension that handles SQLAlchemy database migrations for Flask applications using Alembic. The database operations are provided as command-line arguments under the flask db command.

Installation

Install Flask-Migrate with pip:

pip install Flask-Migrate

Example

This is an example application that handles database migrations through Flask-Migrate:

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///app.db'

db = SQLAlchemy(app)
migrate = Migrate(app, db)

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(128))

With the above application you can create the database or enable migrations if the database already exists with the following command:

$ flask db init

Note that the FLASK_APP environment variable must be set according to the Flask documentation for this command to work. This will add a migrations folder to your application. The contents of this folder need to be added to version control along with your other source files.

You can then generate an initial migration:

$ flask db migrate

The migration script needs to be reviewed and edited, as Alembic currently does not detect every change you make to your models. In particular, Alembic is currently unable to detect indexes. Once finalized, the migration script also needs to be added to version control.

Then you can apply the migration to the database:

$ flask db upgrade

Then each time the database models change repeat the migrate and upgrade commands.

To sync the database in another system just refresh the migrations folder from source control and run the upgrade command.

To see all the commands that are available run this command:

$ flask db --help

Resources

• Documentation
• pypi
• Change Log

Download Details:

Author: miguelgrinberg
Download Link: Download The Source Code
Official Website: https://github.com/miguelgrinberg/Flask-Migrate
License: MIT

#database #sqlalchemy #flask #python #alembic

Top 5 Strategies for Legacy System Migration

http://blogs.rediff.com/shikha07/2020/09/25/top-5-strategies-for-legacy-system-migration/

The people who can truly understand the data are the business people who can decide what data to keep and what data can be thrown away. During the mapping exercise, it is important to involve someone from the business team for future backtracking. It is also helpful to record the mapping decisions and their reasons.

#legacy application migration #legacy application migration services #legacy application migration solution #legacy application modernization #legacy system modernization #legacy system migration

What are the benefits of cloud migration? Reasons you should migrate

The moving of applications, databases and other business elements from the local server to the cloud server called cloud migration. This article will deal with migration techniques, requirement and the benefits of cloud migration.

In simple terms, moving from local to the public cloud server is called cloud migration. Gartner says 17.5% revenue growth as promised in cloud migration and also has a forecast for 2022 as shown in the following image.

#cloud computing services #cloud migration #all #cloud #cloud migration strategy #enterprise cloud migration strategy #business benefits of cloud migration #key benefits of cloud migration #benefits of cloud migration #types of cloud migration

How to Efficiently Choose the Right Database for Your Applications

Finding the right database solution for your application is not easy. Learn how to efficiently find a database for your applications.

Finding the right database solution for your application is not easy. At iQIYI, one of the largest online video sites in the world, we’re experienced in database selection across several fields: Online Transactional Processing (OLTP), Online Analytical Processing (OLAP), Hybrid Transaction/Analytical Processing (HTAP), SQL, and NoSQL.

Today, I’ll share with you:

• What criteria to use for selecting a database.
• What databases we use at iQIYI.
• Some decision models to help you efficiently pick a database.
• Tips for choosing your database.

I hope this post can help you easily find the right database for your applications.

#database architecture #database application #database choice #database management system #database management tool