49 lines
1.5 KiB
Python
49 lines
1.5 KiB
Python
"""数据库引擎与会话管理。
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使用SQLite作为MVP默认存储，保留通过环境变量`DATABASE_URL`切换到PostgreSQL的能力。
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"""
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import os
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from pathlib import Path
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from typing import AsyncGenerator
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from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
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from sqlalchemy.orm import declarative_base
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# 项目根目录，默认将SQLite数据库放在data目录下
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PROJECT_ROOT = Path(__file__).resolve().parent.parent.parent
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DATA_DIR = PROJECT_ROOT / "data"
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DATA_DIR.mkdir(exist_ok=True)
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# 允许通过环境变量覆盖数据库连接串
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DEFAULT_SQLITE_PATH = DATA_DIR / "meetspot.db"
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DATABASE_URL = os.getenv(
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"DATABASE_URL", f"sqlite+aiosqlite:///{DEFAULT_SQLITE_PATH.as_posix()}"
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)
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# 创建异步引擎与会话工厂
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engine = create_async_engine(DATABASE_URL, echo=False, future=True)
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AsyncSessionLocal = async_sessionmaker(
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bind=engine, class_=AsyncSession, expire_on_commit=False, autoflush=False
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)
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# 统一的ORM基类
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Base = declarative_base()
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async def get_db() -> AsyncGenerator[AsyncSession, None]:
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"""FastAPI 依赖：提供数据库会话并确保正确关闭。"""
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async with AsyncSessionLocal() as session:
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yield session
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async def init_db() -> None:
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"""在启动时创建数据库表。"""
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# 延迟导入以避免循环依赖
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from app import models # noqa: F401 确保所有模型已注册
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async with engine.begin() as conn:
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await conn.run_sync(Base.metadata.create_all)
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