mysql單個表內去重多個重復的字段

DELETE from quzhou WHERE (doctorName,firstDepartmentName,secondDepartmentName,hospitalName) in   
(SELECT doctorName,firstDepartmentName,secondDepartmentName,hospitalName from (SELECT doctorName,firstDepartmentName,secondDepartmentName,hospitalName FROM quzhou GROUP BY doctorName,firstDepartmentName,secondDepartmentName,hospitalName HAVING COUNT(*)>1) s1)   
AND  
id NOT in (SELECT id from (SELECT id FROM quzhou GROUP BY doctorName,firstDepartmentName,secondDepartmentName,hospitalName HAVING COUNT(*)>1) s2); 

 查詢重復字段：

select * from quzhou 
where (doctorName,hospitalName) in (select doctorName,hospitalName from quzhou group by doctorName,hospitalName having count(*) > 1);