first-update

backend/app/core/database.py

@@ -0,0 +1,68 @@
+"""
+Database Configuration and Session Management
+支持 SQLite 和 PostgreSQL
+"""
+
+from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker
+from sqlalchemy.orm import DeclarativeBase
+from sqlalchemy import create_engine
+from app.core.config import get_settings
+
+settings = get_settings()
+
+
+def get_engine_config():
+    """根据数据库类型返回引擎配置"""
+    if settings.DATABASE_URL.startswith("sqlite"):
+        return {"echo": settings.DEBUG}
+    else:
+        return {
+            "echo": settings.DEBUG,
+            "pool_pre_ping": True,
+            "pool_size": 10,
+            "max_overflow": 20,
+        }
+
+
+# Async engine for FastAPI
+async_engine = create_async_engine(
+    settings.DATABASE_URL,
+    **get_engine_config()
+)
+
+# Sync engine for migrations
+sync_engine = create_engine(
+    settings.DATABASE_URL_SYNC,
+    echo=settings.DEBUG,
+    pool_pre_ping=True,
+)
+
+
+# Async session factory
+AsyncSessionLocal = async_sessionmaker(
+    async_engine,
+    class_=AsyncSession,
+    expire_on_commit=False,
+    autocommit=False,
+    autoflush=False,
+)
+
+
+class Base(DeclarativeBase):
+    """Base class for all models"""
+    pass
+
+
+async def init_db():
+    """Initialize database tables"""
+    async with async_engine.begin() as conn:
+        await conn.run_sync(Base.metadata.create_all)
+
+
+async def get_db() -> AsyncSession:
+    """Dependency for getting database session"""
+    async with AsyncSessionLocal() as session:
+        try:
+            yield session
+        finally:
+            await session.close()