用于统计每小时订单总数的 MySQL 查询每小时始终返回 1

Question

我有以下查询，该查询应该按小时计算订单总数。

问题是每小时总数始终为 1。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

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

尝试一下