将mysql查询结果保存到同一数据库表中

Question

Trying to calculate the time difference between current time and the user's settime to get results in minutes and it works, but is there a way to save the same result into table column on the latest row?

SELECT settime, TIMESTAMPDIFF(MINUTE,CURRENT_TIMESTAMP(), settime)AS timeleft 
FROM feedtime

On the left side image, it shows result "timeleft" correctly but also an error Current selection does not contain a unique column. Grid edit, checkbox, Edit, Copy and Delete features are not available. Current selection does not contain a unique column. Grid edit, checkbox, Edit, Copy and Delete features are not available. Where as my id column is already set as primary, unique and auto_increment

Is there a way i could take the result and update into right side image shown column as timeleft?

Answer 1

Yes, use an UPDATE statement:

UPDATE feedtime
SET timeleft = TIMESTAMPDIFF(MINUTE, CURRENT_TIMESTAMP(), settime);

Note that MySQL may insist that you add a WHERE clause which uses a condition on the id column, eg

UPDATE feedtime
SET timeleft = TIMESTAMPDIFF(MINUTE, CURRENT_TIMESTAMP(), settime)
WHERE id = 1;

Even if MySQL does not require this, you still might want to add a WHERE clause to limit the scope of the update.