Filter according to the creation time create_time
The original data table
SQL command: find the latest piece of data of user "Sun", and update the password to 456
UPDATE power_user set password='456' where id=(SELECT id from power_user where user_name='Sun' ORDER BY create_time desc limit 1)
另一种方法：
UPDATE power_user set password=‘123’ FROM (SELECT * from power_user WHERE user_name=‘孙’ ORDER BY create_time desc limit 1) as t2 WHERE power_user.id=t2.id
The efficiency of the two methods is about the same.
The password and update time of the updated data sheet have been changed, and the modification is successful.