MySQL 查询按小时计算订单总数 returns 每小时总是 1

Question

我有以下查询，它应该计算每小时的订单总数。

问题是总数总是每小时 1 个。我对工作日有类似的查询，效果很好。以下查询中有什么错误或缺失？

SELECT COUNT(`Orderno`) as 'totals', EXTRACT(HOUR FROM `order_datetime`) as 'hour'
FROM `orders`
GROUP BY `order_datetime`

结果是

totals hour
1      0
1      1
1      2
...

Answer 1

group by hour(order_datetime)

应该做。

Answer 2

SELECT COUNT(`Orderno`) as 'totals', EXTRACT(HOUR FROM `order_datetime`) as   'hour'
FROM `orders`
GROUP BY `order_datetime`,EXTRACT(HOUR FROM `order_datetime`)

试一试

MySQL 查询按小时计算订单总数 returns 每小时总是 1

MySQL query to count total number of orders made by hour returns always 1 for each hour

mysql

datetime

count

hour