split files, database and S3, models

app/database.py

@@ -0,0 +1,15 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker, declarative_base
+from .config import settings
+
+engine = create_engine(settings.database_url)
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+Base = declarative_base()
+
+# 获取数据库连接的依赖项
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()