你好我已经完成了这个完整的连接查询：

SELECT
  F.date AS Campaign_Date,
  F.Store AS AS Campaign_Store,
  F.IMPRESSIONS,
  F.CLICKS,
  F.SPEND,
  C.Date AS visitors_Date,
  C.ANNEE_MOIS,
  C.ANNEE,
  C.MOIS,
  C.Store AS visitors_Store,
  C.FREQUENTATION_Store
FROM
  `project.campaigns`  F
FULL JOIN
  `proiject.visitors` C
ON (
  C.Store= F.Store
  AND C.Date =F.date
  )

现在，我想撤销那些从未匹配过任何 Campaign_Store 的列 FRQ_Store 的值！换句话说，如何检索在完全连接查询中从未匹配的两列的所有值？

谢谢！