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Alembic 学习

Installation and initiate​

pip install alembic
pip install python-decouple # To load environment variables

# Setup project
alembic init migrations

Config​

.env
DATABASE_URL=postgresql://postgres:password@localhost:5432/databasename
env.py
from sqlmodel import SQLModel
from decouple import config

# ...
# Load Database_URL from .env file
DATABASE_URL = config("DATABASE_URL")
# ...
config.set_main_option("sqlalchemy.url", DATABASE_URL)
# ...
# Add 'autogenerate' migration support
from models import Hero
target_metadata = SQLModel.metadata
script.py.mako
# ...
# import sqlalchemy as sa
import sqlmodel
# ${imports if imports else ""}
# ...

Generate migration files​

# Create migration files
alembic revision # Wrong command
alembic revision --autogenerate -m "<migraion_name>"
alembic revision --autogenerate -m "Create hero table"


Upgrade and downgrade migration files​

alembic upgrade head

alembic downgrade head-1
alembic downgrade <commit>

History and info​

alembic history
alembic show <commit>

Resource​