update statement using nested query

Question

I have a table:

mytable:
    id
    userID
    logDate
    lastLogDate

For every row in that table, I want to update the \'lastLogDate\' co

Answer 1

UPDATE mytable mT,
  (SELECT userid,
          MAX(logDate) AS maxDateForUser
   FROM mytable
   GROUP BY userId) t
SET mT.lastLogDate = t.maxDateForUser
WHERE mT.userid = t.userid;