新增databases.py把所有建表基类统一成一个，才可以链接外键。

students/StudentsQuery.sql

@@ -6,7 +6,11 @@ use student_manage_system;
 
 show tables;
 
+drop database  student_manage_system;
+
 drop table students;
 
 select * from students limit 50;
 
+desc students;
+

students/main.py

@@ -5,13 +5,7 @@ from students.model import students_model
 from contextlib import asynccontextmanager
 
 # 合并接口
-@asynccontextmanager
-async def S_Router(Students_API: APIRouter):
-    Base.metadata.create_all(engine1)
-    yield
-    engine1.dispose()
-
-Students_API = APIRouter(lifespan=S_Router)
+Students_API = APIRouter()
 Students_API.include_router(s_api)
 
 # 自测接口