问题描述
我有一个关于 FILL WITH 函数的问题。我需要一个按月分组的查询,其中包含空行以绘制在图表上。我使用 FILL WITH 函数。
CREATE TABLE IF NOT EXISTS fillwith
(
`event_timestamp` Datetime64,`event_date` Date,`event_type` String
)
ENGINE = Memory
一些样本数据
insert into fillwith (event_timestamp,event_date,event_type) values ('2021-01-07 19:14:33.000','2021-01-07','PRODUCT_VIEW');
insert into fillwith (event_timestamp,event_type) values ('2021-02-07 19:14:33.000','2021-02-07','PRODUCT_CLICK');
insert into fillwith (event_timestamp,event_type) values ('2020-11-07 19:14:33.000','2020-11-07',event_type) values ('2020-12-07 19:14:33.000','2020-12-07',event_type) values ('2020-09-07 19:14:33.000','2020-09-07','PRODUCT_VIEW');
间隔一天,我得到一个完整的天数列表,但没有排序,感觉就像是随机的天数
SELECT
toDate(toStartOfInterval(event_date,toIntervalDay(1))) AS date,countIf(event_type = 'PRODUCT_VIEW') AS views,countIf(event_type = 'PRODUCT_CLICK') AS clicks
FROM fillwith
GROUP BY toDate(toStartOfInterval(event_date,toIntervalDay(1)))
ORDER BY date ASC
WITH FILL FROM toDate('2020-01-01') TO toDate('2021-12-01') STEP dateDiff('second',Now(),Now() + toIntervalDay(1))
结果:
┌───────date─┬─views─┬─clicks─┐
│ 2020-09-07 │ 1 │ 0 │
│ 2020-11-07 │ 1 │ 0 │
│ 2020-12-07 │ 1 │ 0 │
│ 2021-01-07 │ 1 │ 0 │
│ 2021-02-07 │ 0 │ 1 │
└────────────┴───────┴────────┘
┌───────date─┬─views─┬─clicks─┐
│ 2106-02-07 │ 0 │ 0 │
│ 2005-05-25 │ 0 │ 0 │
│ 2062-07-09 │ 0 │ 0 │
│ 2106-02-07 │ 0 │ 0 │
│ 1997-05-03 │ 0 │ 0 │
│ 2054-06-17 │ 0 │ 0 │
│ 2106-02-07 │ 0 │ 0 │
│ 1989-04-11 │ 0 │ 0 │
│ 2046-05-26 │ 0 │ 0 │
│ 2103-07-11 │ 0 │ 0 │
当我尝试相同的月间隔时:
select
toDate(toStartOfInterval(event_date,INTERVAL 1 month)) as date,countIf(event_type = 'PRODUCT_VIEW') as views,countIf(event_type = 'PRODUCT_CLICK') as clicks
from fillwith
GROUP BY toDate(toStartOfInterval(event_date,INTERVAL 1 month))
ORDER BY date ASC WITH FILL
FROM toDate('2020-01-01') TO toDate('2021-04-01') STEP dateDiff('second',Now() + INTERVAL 1 month)
结果:
┌───────date─┬─views─┬─clicks─┐
│ 2020-01-01 │ 0 │ 0 │
│ 2020-09-01 │ 1 │ 0 │
│ 2020-11-01 │ 1 │ 0 │
│ 2020-12-01 │ 1 │ 0 │
│ 2021-01-01 │ 1 │ 0 │
│ 2021-02-01 │ 0 │ 1 │
└────────────┴───────┴────────┘
但我希望:
┌───────date─┬─views─┬─clicks─┐
│ 2020-01-01 │ 0 │ 0 │
│ 2020-02-01 │ 0 │ 0 │
│ 2020-03-01 │ 0 │ 0 │
│ 2020-04-01 │ 0 │ 0 │
│ 2020-05-01 │ 0 │ 0 │
│ 2020-06-01 │ 0 │ 0 │
│ 2020-07-01 │ 0 │ 0 │
│ 2020-08-01 │ 0 │ 0 │
│ 2020-09-01 │ 1 │ 0 │
│ 2020-10-01 │ 0 │ 0 │
│ 2020-11-01 │ 1 │ 0 │
│ 2020-12-01 │ 1 │ 0 │
│ 2021-01-01 │ 1 │ 0 │
│ 2021-02-01 │ 0 │ 1 │
│ 2021-03-01 │ 0 │ 0 │
│ 2021-04-01 │ 0 │ 0 │
└────────────┴───────┴────────┘
有人知道为什么会发生这种情况以及我该如何改进吗?
感谢您的帮助!
解决方法
试试这个查询:
WITH toDate(0) AS start_date,toRelativeMonthNum(toDate(0)) AS relative_month_of_start_date
SELECT
addMonths(start_date,relative_month - relative_month_of_start_date) AS month,views,clicks
FROM
(
SELECT
toRelativeMonthNum(event_date) AS relative_month,countIf(event_type = 'PRODUCT_VIEW') AS views,countIf(event_type = 'PRODUCT_CLICK') AS clicks
FROM fillwith
GROUP BY relative_month
ORDER BY relative_month ASC
WITH FILL
FROM toRelativeMonthNum(toDate('2020-01-01'))
TO toRelativeMonthNum(toDate('2021-12-01')) STEP 1
)
ORDER BY month ASC
/*
┌──────month─┬─views─┬─clicks─┐
│ 2020-01-01 │ 0 │ 0 │
│ 2020-02-01 │ 0 │ 0 │
│ 2020-03-01 │ 0 │ 0 │
│ 2020-04-01 │ 0 │ 0 │
│ 2020-05-01 │ 0 │ 0 │
│ 2020-06-01 │ 0 │ 0 │
│ 2020-07-01 │ 0 │ 0 │
│ 2020-08-01 │ 0 │ 0 │
│ 2020-09-01 │ 1 │ 0 │
│ 2020-10-01 │ 0 │ 0 │
│ 2020-11-01 │ 1 │ 0 │
│ 2020-12-01 │ 1 │ 0 │
│ 2021-01-01 │ 1 │ 0 │
│ 2021-02-01 │ 0 │ 1 │
│ 2021-03-01 │ 0 │ 0 │
│ 2021-04-01 │ 0 │ 0 │
│ 2021-05-01 │ 0 │ 0 │
│ 2021-06-01 │ 0 │ 0 │
│ 2021-07-01 │ 0 │ 0 │
│ 2021-08-01 │ 0 │ 0 │
│ 2021-09-01 │ 0 │ 0 │
│ 2021-10-01 │ 0 │ 0 │
│ 2021-11-01 │ 0 │ 0 │
└────────────┴───────┴────────┘
*/
或替代方式:
SELECT
toStartOfMonth(date) AS month,sum(views) AS views,sum(clicks) AS clicks
FROM
(
SELECT
event_date AS date,/* or: toDate(toStartOfDay(event_timestamp)) AS date */
countIf(event_type = 'PRODUCT_VIEW') AS views,countIf(event_type = 'PRODUCT_CLICK') AS clicks
FROM fillwith
GROUP BY date
ORDER BY date ASC
WITH FILL
FROM toDate('2020-01-01')
TO toDate('2021-12-01')
/* type of 'date' is Date => '1' means 1 day */
STEP 1
)
GROUP BY month
ORDER BY month ASC
/*
┌──────month─┬─views─┬─clicks─┐
│ 2020-01-01 │ 0 │ 0 │
│ 2020-02-01 │ 0 │ 0 │
│ 2020-03-01 │ 0 │ 0 │
│ 2020-04-01 │ 0 │ 0 │
│ 2020-05-01 │ 0 │ 0 │
│ 2020-06-01 │ 0 │ 0 │
│ 2020-07-01 │ 0 │ 0 │
│ 2020-08-01 │ 0 │ 0 │
│ 2020-09-01 │ 1 │ 0 │
│ 2020-10-01 │ 0 │ 0 │
│ 2020-11-01 │ 1 │ 0 │
│ 2020-12-01 │ 1 │ 0 │
│ 2021-01-01 │ 1 │ 0 │
│ 2021-02-01 │ 0 │ 1 │
│ 2021-03-01 │ 0 │ 0 │
│ 2021-04-01 │ 0 │ 0 │
│ 2021-05-01 │ 0 │ 0 │
│ 2021-06-01 │ 0 │ 0 │
│ 2021-07-01 │ 0 │ 0 │
│ 2021-08-01 │ 0 │ 0 │
│ 2021-09-01 │ 0 │ 0 │
│ 2021-10-01 │ 0 │ 0 │
│ 2021-11-01 │ 0 │ 0 │
└────────────┴───────┴────────┘
*/