update Xipu.tqx0sn_Change_audit_day as t
    set t.Update_time = X.Update_time 
    X X X  
    select * from (select  Max(A.Update_time) as Update_time , A.Task_number , A.Update  from Xipu.tqx0sn_Change_audit_day A 
    join Xipu.tqx0sn_Change_audit_day B 
    On A.Task_number = B.Task_number  
    And A.Update = B.Update
    And A.Update_time <> B.Update_time
    group by A.Update , A.Task_number

update Xipu.tqx0sn_Change_audit_day as t
set t.Update_time = X.Update_time 
X X X  
select * from (select  Max(A.Update_time) as Update_time , A.Task_number , A.Update  from Xipu.tqx0sn_Change_audit_day A 
join Xipu.tqx0sn_Change_audit_day B 
On A.Task_number = B.Task_number  
And A.Update = B.Update
And A.Update_time <> B.Update_time
group by A.Update , A.Task_number ) X
on t.task_number