Postgres错误：子查询返回的多于一行用作表达式。 21000

Question

我试图在表格中插入不同的行，但是，标题中出现错误。我不明白的是，我已将LIMIT设置为1，因为我认为这可以解决问题。

有人可以阐明这一点吗？

  

错误：子查询返回的多于一行用作表达式。

 INSERT INTO reports.sem_attribution_v2
SELECT DISTINCT
  tsa.user_id,
  tsa.transfer_date,
  tsa.engine,
  tsa.campaign_id,
  tsa.adgroup_id,
  (CASE
    WHEN tsa.engine = 'quora' THEN NULL
    WHEN tsa.source ILIKE '%uac%' THEN (
      SELECT
        account
      FROM reports.lookup_uac_elements
      WHERE campaign_id = tsa.campaign_id
      LIMIT 1)
    WHEN tsa.engine = 'google' THEN (
      SELECT
        pse.account_name
      FROM reports.lookup_paid_search_elements pse
      WHERE pse.campaign_id = tsa.campaign_id
      AND pse.adgroup_id = tsa.adgroup_id
      LIMIT 1)
    WHEN tsa.engine = 'bing' THEN (
      SELECT
        lbe.account_name
      FROM reports.lookup_bing_elements lbe
      WHERE lbe.campaign_id = tsa.campaign_id
      AND lbe.adgroup_id = tsa.adgroup_id
      LIMIT 1
    )
    ELSE NULL
   END) as account_name,
  (
    CASE
      WHEN tsa.engine = 'quora' THEN NULL
      WHEN tsa.source ILIKE '%uac%' THEN (
        SELECT
          lue.campaign
        FROM reports.lookup_uac_elements lue
        WHERE lue.campaign_id = tsa.campaign_id
      )
      WHEN tsa.engine = 'google' THEN (
        SELECT
          pse.campaign_name
        FROM reports.lookup_paid_search_elements pse
        WHERE pse.campaign_id = tsa.campaign_id
        AND pse.adgroup_id = tsa.adgroup_id
        LIMIT 1
      )
      WHEN tsa.engine = 'bing' THEN (
        SELECT
          lbe.campaign_name
        FROM reports.lookup_bing_elements lbe
        WHERE lbe.campaign_id = tsa.campaign_id
        AND lbe.adgroup_id = tsa.adgroup_id
        LIMIT 1
      )
      ELSE NULL
    END
  ) as campaign_name,
  (CASE
    WHEN tsa.engine = 'quora' THEN NULL
    WHEN tsa.source ILIKE '%uac%' THEN NULL
    WHEN tsa.engine = 'google' THEN (
      SELECT
        pse.adgroup_name
      FROM reports.lookup_paid_search_elements pse
      WHERE pse.campaign_id = tsa.campaign_id
      AND pse.adgroup_id = tsa.adgroup_id
      LIMIT 1
    )
    WHEN tsa.engine = 'bing' THEN (
      SELECT
        lbe.adgroup_name
      FROM reports.lookup_bing_elements lbe
      WHERE lbe.campaign_id = tsa.campaign_id
      AND lbe.adgroup_id = tsa.adgroup_id
      LIMIT 1
    )
    ELSE NULL
   END) as adgroup_name,
  tsa.creation_platform,
  tsa.profile_country,
  tsa.ltr_12m,
  tsa.costs_12m,
  tsa.ltv_12m,
  tsa.first_paid_touch,
  tsa.even_weights,
  tsa.first_team_touch,
        (CASE
            WHEN tsa.profile_type = 'business' THEN 1
            ELSE 0
         END) as business,
  tsa.content,
  tsa.ltr_12m_r,
  tsa.costs_12m_r,
  tsa.ltv_12m_r,
        (CASE
            WHEN tsa.profile_type = 'consumer' THEN 1
            ELSE 0
        END) as consumer
FROM tmp_sem_attribution tsa;