Flask - Model, Migration

###1.install install flask-SQLAlchemy and flask_migrate

# terminal
pip install flask-sqlalchemy
pip install flask-migrate

###2.set on __init__py file

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

app = Flask(__name__)
app.config.from_object(Config)
db = SQLAlchemy(app)
migrate = Migrate(app, db)

from myapp import routes, models

##3. Create models.py

• create user model
• what __repr__ do is, in Python cell
  when call user instance, shown as <User username>

from myapp import db

class User(db.Model):
    id  = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), index=True, unique=True)
    email = db.Column(db.String(120), index=True, unique=True)
    password_hash = db.Column(db.String(128))

    def __repr__(self):
        return '<User {}>'.format(self.username)

how to test with Python cell

# > from myapp.models import User
# > u = User(username='susan', email='susan@mail.com')
# > u
# < User susan>

##4. Migration Setup

• Create Directory migrations (first setting)

  # terminal
  ✗ flask db init
  

• Create table name userfi
• it will be added on 'user_table'.py in migrations/versions
• inside of the file, two function will be made; upgrade, downgrade

# terminal
✗ flask db migrate -m "users table"

• Execute the upgrade function to create db sql file
• app.db will be made

  # terminal
  ✗ flask db upgrade