Question

我的table 1如下所示：

+-----------+------------+------------+
| campaign  | start_date |  end_date  |
+-----------+------------+------------+
| campaign1 | 2020-01-01 | 2020-01-03 |
| campaign2 | 2020-01-04 | 2020-01-06 |
| ...       | ...        | ...        |
+-----------+------------+------------+

我想创建table 2，如下所示：

+-----------+------------+
| campaign  |    date    |
+-----------+------------+
| campaign1 | 2020-01-01 |
| campaign1 | 2020-01-02 |
| campaign1 | 2020-01-03 |
| campaign2 | 2020-01-04 |
| campaign2 | 2020-01-05 |
| campaign2 | 2020-01-06 |
| ...       | ...        |
+-----------+------------+

请记住，table 1的行数将为n，并将定期添加。我想使用计划查询来计划table 2的创建。

我和GENERATE_DATE_ARRAY()一起玩过CROSS JOIN UNNEST。我还没有找到一种优雅的方法。有什么建议吗？

Answer 1

[如何]将日期范围转换为日期序列...

以下是BigQuery标准SQL

#standardSQL
WITH `project.dataset.table` AS (
  SELECT 'campaign1' campaign, DATE '2020-01-01' start_date, DATE '2020-01-03' end_date UNION ALL
  SELECT 'campaign2', '2020-01-04', '2020-01-06' 
)
SELECT campaign, day
FROM `project.dataset.table`,
UNNEST(GENERATE_DATE_ARRAY(start_date, end_date)) day
-- ORDER BY campaign, day

有结果

Row campaign    day  
1   campaign1   2020-01-01   
2   campaign1   2020-01-02   
3   campaign1   2020-01-03   
4   campaign2   2020-01-04   
5   campaign2   2020-01-05   
6   campaign2   2020-01-06

更新-在您的实际用例中使用以下内容（上面只是示例，其中包含问题中的伪数据供您测试）

#standardSQL
SELECT campaign, day
FROM `project.dataset.table`,
UNNEST(GENERATE_DATE_ARRAY(start_date, end_date)) day

Answer 2

您可以使用generate_date_array()和unnest()：

select campaign, dte
from (select 'campaign1' as campaign,  date('2020-01-01') as start_date, date('2020-01-03') as end_date
     ) t cross join
     unnest(generate_date_array(t.start_date, t.end_date, interval 1 day)) dte;

Answer 3

另一种方法是创建一个“日历” CTE（或数据库中的表），然后交叉联接并过滤：

with cal as ( select dte from unnest(generate_date_array('2000-01-01','2050-01-01', interval 1 day)) dte),
tbl as (
  select 'campaign1' as campaign, cast('2020-01-01' as date) as start_date, cast('2020-01-03' as date) as end_date union all
  select 'campaign2','2020-01-04','2020-01-06'
)
select campaign, dte from tbl
cross join cal
where dte between start_date and end_date
order by campaign, dte

将日期范围转换为BigQuery中的日期序列

3 个答案: