mysql - 仅更新 MySql 表中的时间戳

Question

鉴于此表

mysql> describe last_user_activity;
+--------------+------------+------+-----+-------------------+-------+
| Field        | Type       | Null | Key | Default           | Extra |
+--------------+------------+------+-----+-------------------+-------+
| customer_id  | int(11)    | NO   |     | NULL              |       |
| token        | text       | NO   |     | NULL              |       |
| time_stamp   | timestamp  | YES  |     | CURRENT_TIMESTAMP |       |
| is_logged_in | tinyint(1) | NO   |     | 0                 |       |
+--------------+------------+------+-----+-------------------+-------+
4 rows in set (0.00 sec)

我想“触摸”表格的一行，将 time_stamp 设置为其默认值 CURRENT_TIMESTAMP。

我想我可以尝试

UPDATE last_user_activity WHERE token="40aed4d9-c9ac-471e-8d53-b2baa0d72523";

(这是表中的有效标记)，但这导致了

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE token="40aed4d9-c9ac-471e-8d53-b2baa0d72523"' at line 1

哦，好吧，这看起来很聪明，但是 NVM。所以，然后我尝试了

UPDATE last_user_activity SET token="40aed4d9-c9ac-471e-8d53-b2baa0d72523" 
       WHERE token="40aed4d9-c9ac-471e-8d53-b2baa0d72523";

表示成功，但是，时间戳字段未更新。

我做错了什么？

Answer 1

UPDATE last_user_activity 
SET time_stamp = NULL
WHERE token="40aed4d9-c9ac-471e-8d53-b2baa0d72523";

或者

UPDATE last_user_activity 
SET time_stamp = NOW()
WHERE token="40aed4d9-c9ac-471e-8d53-b2baa0d72523";