Python-flask-flask-sqlalchemy and Flask-migrate combined for data migration

Steps to use:

1. Introduction of Flask-sqlalchemyfromimport= SQLAlchemy ()　　

2. Register flask-SQLAlchemy    db.init_app (APP)

3. Import the tables in models  fromimport *

4. Write class inherits Db. Model  class  Users (db. Model):    　　__tablename__'users'    = Column (Integer, primary _key=true)

5th step:    Installing PIP3 install Flask-migrate

5.1 Import
Import Migrate, Migratecommand
Import Create_app, DB

   5.2 Creating the Migrate sample
Migrate = Migrate (App, DB)

   5.3 Create DB command
Manager.add_command (' db ', Migratecommand) 

6th step
Execute command:    initial: Python manage.py db init                python manage.py db migrate     #生成数据结构    python manage.py db upgrade 
     #在数据库中创建表信息

7th step:
When executing SQL later:        mode one:            = db.session.query (models. User.id,models. User.Name). All ()
            db.session.remove ()        mode two:            = models. Users.query.all ()

Python-flask-flask-sqlalchemy and Flask-migrate combined for data migration