如何在Bigquery中实现先行查询

SELECT
  user_id,
  event_date,
  event_time,
  event_type,
  LAG(event_type) OVER (PARTITION BY user_id ORDER BY event_date, event_time) AS previous_event
FROM
  `project.dataset.table`

SELECT
  t1.user_id,
  t1.event_date,
  t1.event_time,
  t1.event_type,
  t2.previous_event
FROM
  `project.dataset.table` AS t1
LEFT JOIN
  (
    SELECT
      user_id,
      event_date,
      event_time,
      event_type,
      LAG(event_type) OVER (PARTITION BY user_id ORDER BY event_date, event_time) AS previous_event
    FROM
      `project.dataset.table`
  ) AS t2
ON
  t1.user_id = t2.user_id
  AND t1.event_date = t2.event_date
  AND t1.event_time = t2.event_time