【问题标题】：Support UNION ALL function in BigQuery SQL Issue在 BigQuery SQL 问题中支持 UNION ALL 函数
【发布时间】：2020-11-22 17:38:11
【问题描述】：

如何让这个查询在 GCP 大查询上运行而不会出错：

“不支持引用其他表的相关子查询，除非它们可以去相关，例如通过将它们转换为有效的 JOIN。”

你们有什么想法可以解决这个冲突吗？

 Select
  x.subject_id as PatientId
  ,sum(x.BPS) as sbp
  ,sum(x.RR) as rr
  ,sum(x.sepsis) as sepsis
From (
  Select
    c.subject_id
    ,(
    Select  (Case
      WHEN cast(c2.value as numeric) <= 90 THEN 3
            WHEN cast(c2.value as numeric) >= 91 AND cast(c2.value as numeric) <= 100 THEN 2
            WHEN cast(c2.value as numeric) >= 101 AND cast(c2.value as numeric) < 110 THEN 1
            WHEN cast(c2.value as numeric) >= 111 AND cast(c2.value as numeric) < 219 THEN 0
      WHEN cast(c2.value as numeric) >= 220 THEN 3
      else 0
         End)
    From    chartevents c2
    Where   c2.subject_id = c.subject_id
        and c2.itemid = c.itemid
        limit 1
    ) as BPS
    ,0 as RR
  ,0 as sepsis
  From
    chartevents c
  Where
    c.itemid = 220050
  Group by
    c.subject_id
    ,c.itemid
  Union all
  Select
    c.subject_id
    ,0 as BPS
    ,(Select  (Case
      WHEN cast(c2.value as numeric) <= 8 THEN 3
            WHEN cast(c2.value as numeric) >= 9 AND cast(c2.value as numeric) <= 11 THEN 1
            WHEN cast(c2.value as numeric) >= 12 AND cast(c2.value as numeric) <= 20 THEN 0
            WHEN cast(c2.value as numeric) >= 21 AND cast(c2.value as numeric) <= 24 THEN 2
            WHEN cast(c2.value as numeric) >= 25 THEN 3
      else 0
         End)
    From    chartevents c2
    Where   c2.subject_id = c.subject_id
        and c2.itemid = c.itemid
       limit 1
   ) as RR
  ,0 as sepsis
  From
    chartevents c
  Where
    c.itemid = 220210
  Group by
    c.subject_id
    ,c.itemid
  Union all
    Select
        c.subject_id
        ,0 as BPS
        ,0 as RR
      ,(case when exists (
                      Select  1
                      From    diagnoses_icd d
                      Where   d.subject_id = c.subject_id
                              and d.icd9_code like '%99591%'
                      )
              then 1
              else 0
        end) as sepsis
      From
        chartevents c
      Where
        c.itemid = 228334
      Group by
        c.subject_id
        ,c.itemid
) x
Group by
   x.subject_id
   limit 5
;

期望的输出：

|患者 ID | sbp | rr |败血症|

| 1 | 0 | 0 | 0 |
| 2 | 2 | 3 | 1 |

【问题讨论】：

样本数据和所需结果将使您的问题更容易理解。
除了GMB所说的，我还强烈建议简化查询。
我添加了更多信息。我怎样才能简化这个查询并带来相同的结果。 @GordonLinoff
@ViniciusFerreira。 . .例如，您可能不需要所有列来生成错误。该错误可能仅在union all 的一个子查询中产生。有两个想法。

标签： sql google-bigquery union-all correlated-subquery spring-cloud-gcp-bigquery

【解决方案1】：

这可能是由于chartevents c2 子查询而发生的。尝试将它们转换为ARRAY_AGG 构造。

这会产生错误：

SELECT
  c.subject_id,
  (
      SELECT c2.value * 2
      FROM chartevents c2
      WHERE c2.subject_id = c.subject_id
        AND c2.itemid = c.itemid
      LIMIT 1
  ) as BPS
FROM
  chartevents c

这将起作用：

SELECT
  c.subject_id,
  ARRAY_AGG(c2.value * 2 LIMIT 1)[OFFSET(0)] AS BPS
FROM chartevents AS c
JOIN chartevents AS c2
ON c2.subject_id = c.subject_id
  AND c2.itemid = c.itemid

【讨论】：