问题：对于所有与上级居住在不同城市的工作人员，将其工作人员的姓名列出为“ staff_member”，将主管的姓名列出为“ supervisor”。

关系：

Staff (snum,Name,DOB,Address,City,Gender,Salary,Supervisor,Dnum) 
Dept ( Dnum,Dname,Manager,Mgrstartdate ) 
Deptlocation ( Dnum,Dcity ) 
Project ( Pnum,Pname,Pcity,Dnum ) 
Workson ( snum,Pnum,Hours )

Column Supervisor of table Staff is a foreign key which references column snum of table Staff.
Column Dnum of table Staff is a foreign key which references column Dnum of table Dept.
Column Manager of table Dept is a foreign key which references column snum of table Staff.
Column Dnum of table Deptlocation is a foreign key which references column Dnum of table Dept.
Column Dnum of table Project is a foreign key which references column Dnum of table Dept.
Column snum of table Workson is a foreign key which references column snum of table Staff.
Column Pnum of table Workson is a foreign key which references column Pnum of table Project.

到目前为止，我得到的是：

SELECT name AS staff_member,supervisor
from staff s
INNER JOIN deptlocation d ON s.dnum = d.dnum
WHERE s.city NOT EXISTS (d.city)

我做错了什么？

Error:Your query has syntax errors.
Description:java.sql.SQLException: ORA-00920: invalid relational operator