新增databases.py把所有建表基类统一成一个，才可以链接外键。

main.py

@@ -4,15 +4,19 @@ from scores.main import Scores_API
 from stu_jiuye.main import Shtudent_Jiuye
 from students.main import Students_API
 from Teachers.main import Teachers_API
-
+from databases import *
 app = FastAPI(title="学生管理系统")
 
+Base_all.metadata.create_all(bind=engine_all)
+
 app.include_router(Classes_API,tags=["classes"])
 app.include_router(Scores_API,tags=["scores"])
 app.include_router(Shtudent_Jiuye,tags=["Employments"])
 app.include_router(Students_API,tags=["students"])
 app.include_router(Teachers_API,tags=["teachers"])
 
+
+
 def main():
     print("Hello from student-manage-system!")