Как составить запрос из двух табл?

SELECT *
  FROM `primary`
  WHERE `id` IN (
    SELECT `s`.`primary_id` 
      FROM (
        SELECT `primary_id`, MAX(`datetime`) AS `datetime`
          FROM `secondary`
          GROUP BY `primary_id`
        ) AS `t`
        JOIN `secodary` AS `s` ON `s`.`state` = 1
          AND `s`.`primary_id` = `t`.`primary_id`
          AND `s`.`datetime` = `t`.`datetime`
      )

SELECT *
FROM main m
LEFT JOIN extra e1 ON m.id = e1.main_id
LEFT JOIN extra e2 ON e1.main_id = e2.main_id AND e2.date > e1.date
WHERE e2.date IS NULL AND e1.status = 1;