FastAPIでalembicのautogenerationを適用する方法

とりあえずproject/alembic/env.py の中身

sqlalchemyのmodelを継承して作成したmodelのファイルをimportして設定してあげることが必要なので、下記のようにpathを繋げてあげる。

FastAPIの公式ドキュメントを参考にアーキテクチャ組んでるので画像を参考にautogenerateやってみてくださいー

import os
import sys
from logging.config import fileConfig

from alembic import context
from sqlalchemy import engine_from_config
from sqlalchemy import pool

# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.

# relative importを可能にするための設定。これないと、Module app not found的なエラー出る
sys.path.insert(0, os.path.realpath(os.path.join(os.path.dirname(__file__), '..')))

import importlib
from sqlalchemy.schema import MetaData

config = context.config

# Interpret the config file for Python logging.
# This line sets up loggers basically.
fileConfig(config.config_file_name)

# add your model's MetaData object here
# for 'autogenerate' support
# from myapp import mymodel
# target_metadata = mymodel.Base.metadata

# ここに読み込んで欲しいモデルファイルを記載。
target_models = [
    'app.models'
]


def import_model_bases():
    """import all target models base metadatas."""
    lst = list(map(
        lambda x: importlib.import_module(x).Base.metadata,
        target_models
    ))
    return lst


def combine_metadata(lst):
    m = MetaData()
    for metadata in lst:
        for t in metadata.tables.values():
            t.tometadata(m)
    return m


target_metadata = combine_metadata(import_model_bases())

# other values from the config, defined by the needs of env.py,
# can be acquired:
# my_important_option = config.get_main_option("my_important_option")
# ... etc.


def run_migrations_offline():
    """Run migrations in 'offline' mode.

    This configures the context with just a URL
    and not an Engine, though an Engine is acceptable
    here as well.  By skipping the Engine creation
    we don't even need a DBAPI to be available.

    Calls to context.execute() here emit the given string to the
    script output.

    """
    url = config.get_main_option("sqlalchemy.url")
    context.configure(
        url=url,
        target_metadata=target_metadata,
        literal_binds=True,
        dialect_opts={"paramstyle": "named"},
    )

    with context.begin_transaction():
        context.run_migrations()


def run_migrations_online():
    """Run migrations in 'online' mode.

    In this scenario we need to create an Engine
    and associate a connection with the context.

    """
    connectable = engine_from_config(
        config.get_section(config.config_ini_section),
        prefix="sqlalchemy.",
        poolclass=pool.NullPool,
    )

    with connectable.connect() as connection:
        context.configure(
            connection=connection, target_metadata=target_metadata
        )

        with context.begin_transaction():
            context.run_migrations()


if context.is_offline_mode():
    run_migrations_offline()
else:
    run_migrations_online()

参考記事

Alembicを使う際のメモ