graph_rag_server/alembic/env.py

"""
Alembic 环境配置

本模块配置 Alembic 迁移环境，包括数据库连接和模型元数据。
"""

from logging.config import fileConfig
import os
import sys
from pathlib import Path

from sqlalchemy import engine_from_config
from sqlalchemy import pool

from alembic import context

# 添加项目根目录到 Python 路径
sys.path.insert(0, str(Path(__file__).parent.parent))

# 导入配置和模型
from src.config.settings import get_settings
from src.infrastructure.database.models import Base

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

# Interpret the config file for Python logging.
# This line sets up loggers basically.
if config.config_file_name is not None:
    fileConfig(config.config_file_name)

# 从环境变量获取数据库 URL
settings = get_settings()
config.set_main_option("sqlalchemy.url", settings.database.url)

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

# 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() -> None:
    """
    在 'offline' 模式下运行迁移。

    这会配置上下文只使用 URL，而不是 Engine，
    尽管这里也可以接受 Engine。通过跳过 Engine 的创建，
    我们甚至不需要 DBAPI 可用。

    调用 context.execute() 会将给定的字符串输出到脚本输出。
    """
    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() -> None:
    """
    在 'online' 模式下运行迁移。

    在这种情况下，我们需要创建一个 Engine
    并将连接与上下文关联。
    """
    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()