Joey
51 lines
1.3 KiB
Python
51 lines
1.3 KiB
Python
"""数据库引擎与会话工厂（SQLite 本地过渡 / PostgreSQL 生产）。"""
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from __future__ import annotations
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from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
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from sqlalchemy.orm import DeclarativeBase
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from config import get_settings
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class Base(DeclarativeBase):
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pass
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_engine = None
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_session_factory = None
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def get_engine():
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global _engine
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if _engine is None:
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settings = get_settings()
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connect_args: dict = {}
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# SQLite 需允许多线程/多协程访问同一文件
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if settings.database_url.startswith("sqlite"):
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connect_args["check_same_thread"] = False
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_engine = create_async_engine(
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settings.database_url,
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echo=False,
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future=True,
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connect_args=connect_args,
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)
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return _engine
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def get_session_factory() -> async_sessionmaker[AsyncSession]:
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global _session_factory
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if _session_factory is None:
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_session_factory = async_sessionmaker(
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get_engine(),
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class_=AsyncSession,
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expire_on_commit=False,
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)
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return _session_factory
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async def get_db():
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"""FastAPI 依赖：请求级 AsyncSession。"""
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factory = get_session_factory()
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async with factory() as session:
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yield session
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