错误：SELECT 列表表达式引用了在 [2:49] 处既未分组也未聚合的列 created_utc

Question

我有一张桌子：t

我的目标：仅提取表中得分最高的“id”，并按week_number 对其进行分组。

询问：

SELECT id, 
       CAST(EXTRACT(WEEK FROM TIMESTAMP_SECONDS(created_utc)) AS STRING) AS week_number, 
       MAX(score) AS highest_score
FROM t 
WHERE body='r/twinpeaks'
GROUP BY id;

我收到此错误：错误：SELECT 列表表达式引用列 created_utc，它在 [2:49] 处既未分组也未聚合

我尝试这样做：

SELECT id, 
       CAST(EXTRACT(WEEK FROM TIMESTAMP_SECONDS(created_utc)) AS STRING) AS week_number, 
       MAX(score) AS highest_score
FROM  t 
WHERE body='r/twinpeaks'
GROUP BY week_number, id;

但这就是我得到的：

Row  id            week_number  highest_score    
1    dmkb6sv      36            1    
2    dn1cd2s      37            2    
3    dn43h1k      38            16   
4    dn3xf18      38            1    
5    dn7i1ko      38            1
6    dnpr9b1      39            1

我要这个：

Row  id            week_number  highest_score    
1    dmkb6sv      36            1    
2    dn1cd2s      37            2    
3    dn43h1k      38            16   
6    dnpr9b1      39            1

Answer 1

下面是 BigQuery 标准 SQL

#standardSQL
SELECT 
  EXTRACT(WEEK FROM TIMESTAMP_SECONDS(created_utc)) AS week_number,
  ARRAY_AGG(id ORDER BY score DESC LIMIT 1)[OFFSET(0)] id,
  ARRAY_AGG(score ORDER BY score DESC LIMIT 1)[OFFSET(0)] highest_score    
FROM `project.dataset.table` 
WHERE body = 'r/twinpeaks'
GROUP BY week_number
ORDER BY week_number

Answer 2

您可以尝试ROW_NUMBER在这里使用：

SELECT *
FROM
(
    SELECT id,
        CAST(EXTRACT(WEEK FROM TIMESTAMP_SECONDS(created_utc)) AS STRING) AS week_number,
        score,
        ROW_NUMBER() OVER (PARTITION BY
            CAST(EXTRACT(WEEK FROM TIMESTAMP_SECONDS(created_utc)) AS STRING)
            ORDER BY score DESC) rn
    FROM t 
    WHERE body = 'r/twinpeaks'
) t
WHERE rn = 1;

这将返回每个周数中得分最高的记录。我在这里假设您要么首先不关心关系，要么关系不会发生。如果您需要处理平局，则可以使用排名函数来代替行号。