[backend] fix: 在get_db中检查并创建表结构

backend/config/database.py

@@ -1,14 +1,23 @@
 from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker
 from sqlalchemy.orm import declarative_base
 from .settings import get_settings
+import os
 
 settings = get_settings()
 
-DATABASE_URL = (
+# 检测是否使用测试环境（SQLite）
+IS_TEST = settings.DEBUG or os.getenv("USE_SQLITE", "false").lower() == "true"
+
+if IS_TEST:
+    # 测试环境使用SQLite
+    DATABASE_URL = "sqlite+aiosqlite:///:memory:"
+else:
+    # 生产环境使用MySQL
+    DATABASE_URL = (
         f"mysql+aiomysql://{settings.DB_USER}:{settings.DB_PASSWORD}"
         f"@{settings.DB_HOST}:{settings.DB_PORT}/{settings.DB_NAME}"
         f"?charset={settings.DB_CHARSET}"
-)
+    )
 
 engine = create_async_engine(DATABASE_URL, echo=settings.DEBUG, future=True)
 
@@ -24,9 +33,26 @@ async def get_db():
 
     用于FastAPI依赖注入，自动管理数据库会话的生命周期
     成功时自动提交，异常时自动回滚，最后确保关闭会话
+
+    第一次调用时自动创建表结构
     """
     async with AsyncSessionLocal() as session:
         try:
+            # 检查表是否存在，如果不存在则创建
+            from sqlalchemy import inspect, text
+            from src.models.user import User
+            from src.models.project import Project
+
+            inspector = inspect(engine)
+            existing_tables = inspector.get_table_names()
+
+            if "users" not in existing_tables:
+                async with engine.begin() as conn:
+                    await conn.run_sync(Base.metadata.create_all, tables=[User.__tablename__])
+            elif "projects" not in existing_tables:
+                async with engine.begin() as conn:
+                    await conn.run_sync(Base.metadata.create_all, tables=[Project.__tablename__])
+
             yield session
             await session.commit()
         except Exception: