之前已经实现了Flask中通过SQLAlchemy中建立表，列，去操作数据库，保存了一些数据
现在需要更新数据库的模型，更新表中某些字段
但是希望保留之前的数据。
之前也听说过一些，升级数据库，且保留数据的技术和框架：
中提到的：
Alembic
但是一直没去用。
Flask SQLAlchemy 升级数据库 保留数据
数据库 — flask mega-tutorial 1.0 documentation
Flask 数据库迁移工具 flask-migrate – 非梦的花朵 (Kevin QQ) – 博客频道 – CSDN.NET
python – 当SQLAlchemy修改了模型结构后，如何更新到已有数据表 – SegmentFault
然后去：
［已解决］SQLAlchemy的数据库迁移工具：Flask-Migrate vs Alembic
alembic 0.8.7 : Python Package Index
－》
Welcome to Alembic’s documentation! — Alembic 0.8.8 documentation
Front Matter — Alembic 0.8.8 documentation
https://bitbucket.org/zzzeek/alembic/get/master.tar.gz
Tutorial — Alembic 0.8.8 documentation
－》作者的帖子里面，解释的很详细了：
Flask-Migrate: Alembic database migration wrapper for Flask – miguelgrinberg.com
以及：
去参考，去使用：
(SIPEvents) ➜ SIPEvents pip install Flask-Migrate Collecting Flask-Migrate Downloading Flask-Migrate-2.0.0.tar.gz Requirement already satisfied (use –upgrade to upgrade): Flask>=0.9 in /root/Envs/SIPEvents/lib/python2.7/site-packages (from Flask-Migrate) Requirement already satisfied (use –upgrade to upgrade): Flask-SQLAlchemy>=1.0 in /root/Envs/SIPEvents/lib/python2.7/site-packages (from Flask-Migrate) Collecting alembic>=0.6 (from Flask-Migrate) Downloading alembic-0.8.7.tar.gz (968kB) 100% |████████████████████████████████| 972kB 128kB/s Collecting Flask-Script>=0.6 (from Flask-Migrate) Downloading Flask-Script-2.0.5.tar.gz (42kB) 100% |████████████████████████████████| 51kB 165kB/s Requirement already satisfied (use –upgrade to upgrade): itsdangerous>=0.21 in /root/Envs/SIPEvents/lib/python2.7/site-packages (from Flask>=0.9->Flask-Migrate) Requirement already satisfied (use –upgrade to upgrade): Jinja2>=2.4 in /root/Envs/SIPEvents/lib/python2.7/site-packages (from Flask>=0.9->Flask-Migrate) Requirement already satisfied (use –upgrade to upgrade): Werkzeug>=0.7 in /root/Envs/SIPEvents/lib/python2.7/site-packages (from Flask>=0.9->Flask-Migrate) Requirement already satisfied (use –upgrade to upgrade): click>=2.0 in /root/Envs/SIPEvents/lib/python2.7/site-packages (from Flask>=0.9->Flask-Migrate) Requirement already satisfied (use –upgrade to upgrade): SQLAlchemy>=0.7 in /root/Envs/SIPEvents/lib/python2.7/site-packages (from Flask-SQLAlchemy>=1.0->Flask-Migrate) Collecting Mako (from alembic>=0.6->Flask-Migrate) Downloading Mako-1.0.4.tar.gz (574kB) 100% |████████████████████████████████| 583kB 108kB/s Collecting python-editor>=0.3 (from alembic>=0.6->Flask-Migrate) Downloading python-editor-1.0.1.tar.gz Requirement already satisfied (use –upgrade to upgrade): MarkupSafe in /root/Envs/SIPEvents/lib/python2.7/site-packages (from Jinja2>=2.4->Flask>=0.9->Flask-Migrate) Building wheels for collected packages: Flask-Migrate, alembic, Flask-Script, Mako, python-editor Running setup.py bdist_wheel for Flask-Migrate … done Stored in directory: /root/.cache/pip/wheels/8d/c7/42/dd3e625605b37b092d5471f172e8e525ea7d996afbb70c304d Running setup.py bdist_wheel for alembic … done Stored in directory: /root/.cache/pip/wheels/48/b0/eb/702f60b92527a913f024d250e437f3bcbbc4a24df618593bca Running setup.py bdist_wheel for Flask-Script … done Stored in directory: /root/.cache/pip/wheels/e2/ea/d8/8d114e46cef819f7d9879504a7f9cb2a88a479af2858223d9f Running setup.py bdist_wheel for Mako … done Stored in directory: /root/.cache/pip/wheels/2a/fa/9a/7030d96d3c51f433848e4cd67a353a411ba6deb5c14e150730 Running setup.py bdist_wheel for python-editor … done Stored in directory: /root/.cache/pip/wheels/c2/49/ce/59657468e42b41eb86aa654650afdf5fe891822a0dc376eebe Successfully built Flask-Migrate alembic Flask-Script Mako python-editor Installing collected packages: Mako, python-editor, alembic, Flask-Script, Flask-Migrate Successfully installed Flask-Migrate-2.0.0 Flask-Script-2.0.5 Mako-1.0.4 alembic-0.8.7 python-editor-1.0.1 |
装了：
- Flask-Migrate-2.0.0
以及对应的依赖：
- Flask-Script-2.0.5
- Mako-1.0.4
- alembic-0.8.7
- python-editor-1.0.1
然后代码：
#!flask/bin/python # -*- coding: UTF-8 -*- from flask import Flask from flask_sqlalchemy import SQLAlchemy from flask_script import Manager from flask_migrate import Migrate, MigrateCommand from sipevents import db from sipevents import app from sipevents import models from sipevents import User, Event # app = Flask(__name__) # app.config[‘SQLALCHEMY_DATABASE_URI’] = ‘sqlite:///app.db’ # db = SQLAlchemy(app) migrate = Migrate(app, db) app.logger.debug(“type(migrate)=%s, migrate=%s”, type(migrate), migrate) manager = Manager(app) app.logger.debug(“type(manager)=%s, manager=%s”, type(manager), manager) manager.add_command(‘db’, MigrateCommand) app.logger.debug(“type(manager)=%s, manager=%s”, type(manager), manager) if __name__ == ‘__main__’: manager.run() |
运行结果：
(SIPEvents) ➜ SIPEvents python db_manager.py <div–<—————————————————————————— DEBUG in __init__ [/usr/share/nginx/html/SIPEvents/sipevents/__init__.py:21]: images=<flask_images.core.Images object at 0x7fa6e23db4d0> <div–<—————————————————————————— <div–<—————————————————————————— DEBUG in __init__ [/usr/share/nginx/html/SIPEvents/sipevents/__init__.py:24]: db=<SQLAlchemy engine=’sqlite:////usr/share/nginx/html/SIPEvents/instance/sipevents.db’> <div–<—————————————————————————— <div–<—————————————————————————— DEBUG in db_manager [db_manager.py:19]: type(migrate)=<class ‘flask_migrate.Migrate’>, migrate=<flask_migrate.Migrate object at 0x7fa6e2601390> <div–<—————————————————————————— <div–<—————————————————————————— DEBUG in db_manager [db_manager.py:22]: type(manager)=<class ‘flask_script.Manager’>, manager=<flask_script.Manager object at 0x7fa6e0be0610> <div–<—————————————————————————— <div–<—————————————————————————— DEBUG in db_manager [db_manager.py:24]: type(manager)=<class ‘flask_script.Manager’>, manager=<flask_script.Manager object at 0x7fa6e0be0610> <div–<—————————————————————————— usage: db_manager.py [-?] {shell,db,runserver} … positional arguments: {shell,db,runserver} shell Runs a Python shell inside Flask application context. db Perform database migrations runserver Runs the Flask development server i.e. app.run() optional arguments: -?, –help show this help message and exit |
(SIPEvents) ➜ SIPEvents python db_manager.py db init <div–<—————————————————————————— DEBUG in __init__ [/usr/share/nginx/html/SIPEvents/sipevents/__init__.py:21]: images=<flask_images.core.Images object at 0x7f0bad2704d0> <div–<—————————————————————————— <div–<—————————————————————————— DEBUG in __init__ [/usr/share/nginx/html/SIPEvents/sipevents/__init__.py:24]: db=<SQLAlchemy engine=’sqlite:////usr/share/nginx/html/SIPEvents/instance/sipevents.db’> <div–<—————————————————————————— <div–<—————————————————————————— DEBUG in db_manager [db_manager.py:19]: type(migrate)=<class ‘flask_migrate.Migrate’>, migrate=<flask_migrate.Migrate object at 0x7f0bad496390> <div–<—————————————————————————— <div–<—————————————————————————— DEBUG in db_manager [db_manager.py:24]: type(manager)=<class ‘flask_script.Manager’>, manager=<flask_script.Manager object at 0x7f0baba75610> <div–<—————————————————————————— Creating directory /usr/share/nginx/html/SIPEvents/migrations … done Creating directory /usr/share/nginx/html/SIPEvents/migrations/versions … done Generating /usr/share/nginx/html/SIPEvents/migrations/README … done Generating /usr/share/nginx/html/SIPEvents/migrations/env.py … done Generating /usr/share/nginx/html/SIPEvents/migrations/env.pyc … done Generating /usr/share/nginx/html/SIPEvents/migrations/alembic.ini … done Generating /usr/share/nginx/html/SIPEvents/migrations/script.py.mako … done Please edit configuration/connection/logging settings in ‘/usr/share/nginx/html/SIPEvents/migrations/alembic.ini’ before proceeding. |
去看了看对应的文件：
(SIPEvents) ➜ SIPEvents ll migrations total 24K -rw-r–r– 1 root root 770 Aug 29 18:04 alembic.ini -rwxr-xr-x 1 root root 2.9K Aug 29 18:04 env.py -rw-r–r– 1 root root 2.7K Aug 29 18:04 env.pyc -rwxr-xr-x 1 root root 38 Aug 29 18:04 README -rwxr-xr-x 1 root root 412 Aug 29 18:04 script.py.mako drwxr-xr-x 2 root root 4.0K Aug 29 18:04 versions (SIPEvents) ➜ SIPEvents ll migrations/versions total 0 (SIPEvents) ➜ SIPEvents cat migrations/alembic.ini # A generic, single database configuration. [alembic] # template used to generate migration files # file_template = %%(rev)s_%%(slug)s # set to ‘true’ to run the environment during # the ‘revision’ command, regardless of autogenerate # revision_environment = false # Logging configuration [loggers] keys = root,sqlalchemy,alembic [handlers] keys = console [formatters] keys = generic [logger_root] level = WARN handlers = console qualname = [logger_sqlalchemy] level = WARN handlers = qualname = sqlalchemy.engine [logger_alembic] level = INFO handlers = qualname = alembic [handler_console] class = StreamHandler args = (sys.stderr,) level = NOTSET formatter = generic [formatter_generic] format = %(levelname)-5.5s [%(name)s] %(message)s datefmt = %H:%M:%S |
(SIPEvents) ➜ SIPEvents python db_manager.py db migrate <div–<—————————————————————————— DEBUG in __init__ [/usr/share/nginx/html/SIPEvents/sipevents/__init__.py:21]: images=<flask_images.core.Images object at 0x7fc7f52684d0> <div–<—————————————————————————— <div–<—————————————————————————— DEBUG in __init__ [/usr/share/nginx/html/SIPEvents/sipevents/__init__.py:24]: db=<SQLAlchemy engine=’sqlite:////usr/share/nginx/html/SIPEvents/instance/sipevents.db’> <div–<—————————————————————————— <div–<—————————————————————————— DEBUG in db_manager [db_manager.py:19]: type(migrate)=<class ‘flask_migrate.Migrate’>, migrate=<flask_migrate.Migrate object at 0x7fc7f548e390> <div–<—————————————————————————— <div–<—————————————————————————— DEBUG in db_manager [db_manager.py:22]: type(manager)=<class ‘flask_script.Manager’>, manager=<flask_script.Manager object at 0x7fc7f3a6d610> <div–<—————————————————————————— <div–<—————————————————————————— DEBUG in db_manager [db_manager.py:24]: type(manager)=<class ‘flask_script.Manager’>, manager=<flask_script.Manager object at 0x7fc7f3a6d610> <div–<—————————————————————————— INFO [alembic.runtime.migration] Context impl SQLiteImpl. INFO [alembic.runtime.migration] Will assume non-transactional DDL. INFO [alembic.env] No changes in schema detected. |
去更改：
/Users/crifan/dev/dev_root/daryun/SIPEvents/sourcecode/flask/sipevents/models.py
添加：notification_time