用于计算按小时返回的订单总数的MySQL查询每小时返回1

Question

我有以下查询，该查询应该按小时计算订单总数。

问题是总数总是每小时1。我有类似的工作日查询，工作得很好。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

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`)

试试吧

Answer 2

group by hour(order_datetime)

应该这样做。