在BigQuery(SQL)中填写缺少的日期而不创建新的日历

时间:2018-11-15 12:06:27

标签: sql google-bigquery missing-data google-data-studio

我正在尝试创建一个SQL,以便可以在与BigQuery连接的Google Data Studio中创建时间序列图。您可以在下面看到我的SQL。

datetime

我得到此表。

select DATEADD(month, DATEDIFF(month, -1, getdate()), 0) + cast(cast(getdate() as time) as datetime)

如您所见,我缺少日期,例如在21.07和24.07之间。如何用前一天的数据填写那些缺失的日期?因为在数据工作室中,那些日子我缺少数据,我也可以将它们设置为0,但我不希望这样。

1 个答案:

答案 0 :(得分:1)

以下内容适用于BigQuery标准SQL,并基于您的当前结果

#standardSQL
WITH your_current_result AS (
  ......
), days AS (
  SELECT day
  FROM (
    SELECT 
      MIN(DATE(TIMESTAMP(ProgressDate))) min_dt, 
      MAX(DATE(TIMESTAMP(ProgressDate))) max_dt
    FROM your_current_result
  ), UNNEST(GENERATE_DATE_ARRAY(min_dt, max_dt)) day
)
SELECT day, 
  LAST_VALUE(EstMin IGNORE NULLS) OVER(ORDER BY day) EstMin,
  LAST_VALUE(EstMax IGNORE NULLS) OVER(ORDER BY day) EstMax
FROM days
LEFT JOIN your_current_result
ON day = DATE(TIMESTAMP(ProgressDate))
-- ORDER BY day   

您可以使用问题中的输出示例进行测试,玩转

#standardSQL
WITH your_current_result AS (
  SELECT '2017-07-21T00:00:00Z' ProgressDate, 0.125 EstMin, 0.25 EstMax UNION ALL
  SELECT '2017-07-24T00:00:00Z', 5.125, 5.375 UNION ALL
  SELECT '2017-07-25T00:00:00Z', 8.75, 10.25 UNION ALL
  SELECT '2017-07-26T00:00:00Z', 10.0, 12.0 UNION ALL
  SELECT '2017-07-27T00:00:00Z', 10.5, 12.75 UNION ALL
  SELECT '2017-08-01T00:00:00Z', 15.25, 19.125 UNION ALL
  SELECT '2017-08-02T00:00:00Z', 15.5, 19.375 UNION ALL
  SELECT '2017-08-05T00:00:00Z', 16.25, 20.625 
), days AS (
  SELECT day
  FROM (
    SELECT 
      MIN(DATE(TIMESTAMP(ProgressDate))) min_dt, 
      MAX(DATE(TIMESTAMP(ProgressDate))) max_dt
    FROM your_current_result
  ), UNNEST(GENERATE_DATE_ARRAY(min_dt, max_dt)) day
)
SELECT day, 
  LAST_VALUE(EstMin IGNORE NULLS) OVER(ORDER BY day) EstMin,
  LAST_VALUE(EstMax IGNORE NULLS) OVER(ORDER BY day) EstMax
FROM days
LEFT JOIN your_current_result
ON day = DATE(TIMESTAMP(ProgressDate))
ORDER BY day  

有结果

Row day         EstMin  EstMax   
1   2017-07-21  0.125   0.25     
2   2017-07-22  0.125   0.25     
3   2017-07-23  0.125   0.25     
4   2017-07-24  5.125   5.375    
5   2017-07-25  8.75    10.25    
6   2017-07-26  10.0    12.0     
7   2017-07-27  10.5    12.75    
8   2017-07-28  10.5    12.75    
9   2017-07-29  10.5    12.75    
10  2017-07-30  10.5    12.75    
11  2017-07-31  10.5    12.75    
12  2017-08-01  15.25   19.125   
13  2017-08-02  15.5    19.375   
14  2017-08-03  15.5    19.375   
15  2017-08-04  15.5    19.375   
16  2017-08-05  16.25   20.625