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

You can do this:

UPDATE t
SET t.logDate = t2.LatestDate
FROM YourTable t
INNER JOIN
(
    SELECT userID, MAX(LogDate) LatestDate
    FROM YourTable
    GROUP BY userID
) t2 ON t.userID = t2.userID;