sql / php - 为unixtimestamps添加4天，具有不同的开始日期

Question

I have a database with 30k+ users. I wish to add 4 days to a time I have stored for each user in unixtimestamp.

The time represent when they have joined, therefore each timestamp is different than the other.

Can I, simply, add 4 days to ALL of these timestamp via. SQL?

Answer 1

Yes you can

UPDATE yourtable SET yourfield = yourfield + 345600

or you calculate it directly in your query.

UPDATE yourtable SET yourfield = yourfield + (60*60*24*4)

But you should make some tests before.