get_db() 依赖注入增加 try/except/rollback/finally: - 请求处理中发生异常时自动 rollback - 无论成功或异常,finally 中确保 close 释放连接 - 防止异常导致连接泄漏或脏事务残留
31 lines
1015 B
Python
31 lines
1015 B
Python
"""数据库连接 — 异步引擎 + 连接池"""
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from sqlalchemy.ext.asyncio import create_async_engine, async_sessionmaker, AsyncSession
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from app.core.config import settings
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engine = create_async_engine(
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settings.DATABASE_URL,
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echo=settings.DEBUG,
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pool_size=20, # 连接池常驻连接数
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max_overflow=10, # 超出 pool_size 时最多再创建的连接数
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pool_recycle=3600, # 连接回收时间(秒),防止 MySQL 8 小时断连
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pool_pre_ping=True, # 每次取出连接前先 ping 检测可用性
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)
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AsyncSessionLocal = async_sessionmaker(
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engine,
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class_=AsyncSession,
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expire_on_commit=False,
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)
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async def get_db() -> AsyncSession:
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"""FastAPI 依赖注入:每次请求获取一个数据库会话(带事务安全兜底)"""
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async with AsyncSessionLocal() as session:
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try:
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yield session
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except Exception:
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await session.rollback()
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raise
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finally:
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await session.close()
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