sqlalchemy Alembic 学习笔记
前一段时间 一直用sqlalchemy-migrate 这个工具来做migrate,不过感觉不太好用。
今天开始学习Alembic 这个工具,由sqlalchemy 的作者一手开发的。
官方Tutorial:http://alembic.readthedocs.org/en/latest/tutorial.html
一: 安装
ubuntu@yee:~$ sudo pip install alembic
二、初始化:
ubuntu@yee:~/project$ alembic init alembic
回到project 主目录 : vim alembic.ini # A generic, single database configuration. [alembic] # path to migration scripts script_location = 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 #sqlalchemy.url = driver://user:pass@localhost/dbname sqlalchemy.url = mysql://root:*********@localhost:3306/dbname
三、使用
alembic revision -m "create friendship table"
vim alembic/versions/96274508199_create_friendship_table.py
import datetime
def upgrade(): op.create_table( 'friendship',
sa.Column('id',sa.Integer,primary_key=True),
sa.Column('me',sa.Integer,sa.ForeignKey('users.id')),
sa.Column('friend',sa.Integer,sa.ForeignKey('users.id')),
sa.Column('created', sa.DateTime, nullable=False,default=datetime.datetime.now()),
)
def downgrade(): op.drop_table('friendship')
四、生成表:
alembic upgrade head
例二:添加字段:
def upgrade(): op.add_column('users', sa.Column('created',sa.DateTime,default=datetime.datetime.now(),nullable=False)) op.add_column( 'users', sa.Column('last_login' ,sa.String(250),nullable=False)) op.add_column('users', sa.Column('registration_ip' ,sa.String(250),nullable=False)) op.add_column( 'users', sa.Column('last_login_ip' ,sa.String(250),nullable=False)) def downgrade(): op.drop_column('users', 'created' ) op.drop_column('users', 'last_login') op.drop_column('users', 'registration_ip') op.drop_column('users', 'last_login_ip')
alembic upgrade +1
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