WITH user_activity(ua_name, ua_first_edit, ua_last_edit) AS

(

  SELECT REPLACE(actor_name, '_', ' '), MIN(rev_timestamp), MAX(rev_timestamp)

  FROM pagelinks

  JOIN page ON page_id = pl_from and page_namespace = 2 AND page_title = 'WhatamIdoing/Sandbox_3'

  JOIN linktarget ON lt_id = pl_target_id AND lt_namespace = 2

  JOIN actor_revision ON actor_name = REPLACE(lt_title, '_', ' ')

  JOIN revision_userindex ON rev_actor = actor_id

  GROUP BY actor_name

)

SELECT ua_name,

       CAST(ua_first_edit AS DATETIME) as first_live_edit,

       CAST(ua_last_edit AS DATETIME) as last_live_edit,

       FLOOR(DATEDIFF(ua_last_edit, ua_first_edit) / 365.25) AS diff_years,

       FLOOR(DATEDIFF(ua_last_edit, ua_first_edit) / (365.25 / 12)) % 12 AS diff_months,

       FLOOR(DATEDIFF(ua_last_edit, ua_first_edit) % (365.25 / 12)) AS diff_days

FROM user_activity;