[Source] Mysql CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP differentiated

When creating a time field

DEFAULT CURRENT_TIMESTAMP
This means that when inserting data, the default value of this field is the current time

ON UPDATE CURRENT_TIMESTAMP
This means that every time this data is updated, the field will be updated to the current time

These two operations are maintained by the MySQL database itself, so you can generate two fields, Creation Time and Update Time, based on this feature, without code to maintain