單查詢來獲取的過去7天個人數

Question

我知道下面的情況將在過去7天

SELECT count(id) FROM registration 
WHERE createdDate BETWEEN DATE_SUB(CURDATE(), INTERVAL 7 DAY) AND CURDATE() 

返回總數是沒有辦法，我可以做的就是一個查詢過去7天每天都有7項結果返回？

例如：

day 1 - 10 
day 2 - 5 
day 3 - 9 
.. 
.. 
.. 

Answer 1

這會給你的日期和數量。

SELECT DATE(createdDate),COUNT(id) 
FROM registration 
WHERE createdDate BETWEEN DATE_SUB(CURDATE(), INTERVAL 7 DAY) AND CURDATE() 
GROUP BY DATE(createdDate) 

或者給更接近你的例子因此你可以使用：

SELECT CONCAT("Day ",DATEDIFF(NOW(), createdDate)) AS day,COUNT(id) 
FROM registration 
WHERE createdDate BETWEEN DATE_SUB(CURDATE(), INTERVAL 7 DAY) AND CURDATE() 
GROUP BY DATE(createdDate) 

Answer 2

添加組by語句：

SELECT count(id), DATE(createdDate) 
FROM registration 
WHERE createdDate BETWEEN DATE_SUB(CURDATE(), INTERVAL 7 DAY) AND CURDATE() 
GROUP BY DATE(createdDate) 

Answer 3

select 8 - n day, count(id) 
from registration 
join (select 1 n union select 2 union select 3 union select 4 union select 5 union select 6 union select 7) x 
on createdDate between date_sub(curdate(), interval n day) and date_sub(curdate(), interval n-1 day) 
group by day 
order by day