MySQL的柱（時間戳）也自動地與系統當前時間更新

Question

如何來當我更新一列但另一列（時間戳）也自動地與系統當前時間

數據庫MySQL的更新：

例如SQL我excuted

select id, processstatus, processtimestamp from mytable where id=229; 

id  processstatus                      processtimestamp   
--------- ---------------------------------------------------------------------------------------------------- ------------------------- 
229  EXPORT_FILEA.txt                      2015-11-04 12:54:49.0 





update mytable set processstatus='EXPORT_TO_FILE_B' where id=229; 

select id, processstatus, processtimestamp from mytable where id=229; 

id  processstatus                      processtimestamp   
--------- ---------------------------------------------------------------------------------------------------- ------------------------- 
229  EXPORT_TO_FILE_B                      2015-11-04 13:09:41.0  

Answer 1

語句，您可以像創建CURRENT_TIMESTAMP列： -

ALTER TABLE `table` ADD `col_name` DATETIME 
on update CURRENT_TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ; 

嘗試此查詢： -

ALTER TABLE `table` CHANGE `col_name` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP; 

刪除on update CURRENT_TIMESTAMP