Flask中模型类的数据库迁移操作Flask-Migrate和Flask-Script | 附知识图

本文链接：https://blog.youkuaiyun.com/iehadoop/article/details/82974979

知识图总览：注意进入项目虚拟环境后在执行迁移

1- 准备工作使用orm创建原始表并添加数据

终端连接数据库并做如下操作

Pycharm运行如下代码

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)


class Config(object):
    SQLALCHEMY_DATABASE_URI = "mysql://root:mysql@127.0.0.1:3306/author"
    SQLALCHEMY_TRACK_MODIFICATIONS = True

app.config.from_object(Config)

db = SQLAlchemy(app)


class Author(db.Model):
    """作者"""
    __tablename__ = "tbl_authors"

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(32), unique=True)

if __name__ == '__main__':
    db.drop_all()
    db.create_all()

    au_xi = Author(name='我吃西红柿')
    au_qian = Author(name='萧潜')
    au_san = Author(name='唐家三少')
    db.session.add_all([au_xi, au_qian, au_san])
    db.session.commit()

    app.run(debug=True)

终端再次查看，发现已经有了表与数据

2- 执行数据库迁移给原始表添加email字段并关联模型类的orm映射

原始代码更改为如下内容，文件命名为 tt.py

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

from flask_script import Manager
from flask_migrate import MigrateCommand, Migrate


app = Flask(__name__)


class Config(object):
    SQLALCHEMY_DATABASE_URI = "mysql://root:mysql@127.0.0.1:3306/author"
    SQLALCHEMY_TRACK_MODIFICATIONS = True

app.config.from_object(Config)

db = SQLAlchemy(app)
manager = Manager(app)  # 创建启动命令管理对象

Migrate(app, db)  # 创建数据库迁移工具对象
manager.add_command("db", MigrateCommand)  # 向启动命令管理对象中添加迁移命令


class Author(db.Model):
    """作者"""
    __tablename__ = "tbl_authors"

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(32), unique=True)
    email = db.Column(db.String(128), unique=True)  # 新增email字段

if __name__ == '__main__':
    manager.run()  # 使用命令行方式启动