Hi all, I need your important help.

Why this query is wrong?

The column `name` is selected in the query or not ?

Many thanks

Code:
mysql> UPDATE `tb1` t
JOIN(

		SELECT
			name,
			DATEDIFF(CURRENT_DATE(), `maxdata`) `dateDiff`
		FROM
	(
				SELECT
					name,
					MAX(`myDates`)`maxdata`
				FROM
					tb2
				GROUP BY
					name
				ORDER BY
					`maxdata` ASC

	)q
)x
SET t.GG = q.`dateDiff`
WHERE
   t.name = q.name;
1054 - Unknown column 'q.name' in 'where clause'