Question

我有一个订单表，它有一个名为order_date的日期时间列。我想计算2009年每个月的订单数量。我该怎么做？

Answer 1

select month(order_date) as orderMonth, count(*) as orderCount
from order
where year(order_date) = 2009
group by month(order_date)
order by month(order_date)

供参考，请参阅Transact-SQL中的month和year命令。

Answer 2

SELECT MONTH(order_date) AS ordermonth, 
   COUNT(*) AS ordercount 
FROM order 
WHERE YEAR(order_date) = 2009 
GROUP BY ordermonth;

Answer 3

使用一些整洁的DATETIME技巧怎么样？

select 
    DATEADD(MONTH, DATEDIFF(MONTH, 0, order_date), 0) AS orderMonth, count(*) as orderCount
from 
    [order]
where 
    order_date >= '2009-01-01'
group by 
    DATEADD(MONTH, DATEDIFF(MONTH, 0, order_date), 0)
order by 
    orderMonth

计算一个月内的条目数

3 个答案: