选择和计算过去30天的所有订单

Question

我目前正在尝试获取过去30天的所有订单，并返回总数和订单数。如果一天没有订单，我仍然需要在结果中显示一行（显然计数和总计== 0）。

有没有办法做到这一点？

有很多问题要求不需要总是获得30行。但是，我不能评论他们，因为我的声誉太低。

例如： selecting all orders for last 30 days, and counting how many per day

Answer 1

天发电机就是从这里generate days from date range

采取的另一项工作是简单的左加入到分组的订单

（左与表和列名称的变化联接子查询）

select a.Date, pr.orders_count, pr.price 
from (
    select curdate() - INTERVAL (a.a + (10 * b.a) + (100 * c.a)) DAY as Date 
    from (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) as a 
    cross join (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) as b 
    cross join (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) as c 
) a 
left join (select order_time, count(*) as orders_count, sum(price) as price from orders group by order_time) pr 
on a.Date = pr.order_time 
where a.Date >= NOW() - INTERVAL 30 DAY 
order by a.Date desc 

Answer 2

可以使用发电机的日期从Get a list of dates between two dates

后，您可以使用outter加入您的订单表。

Answer 3

您可以为此使用日历表或日期维度。

select td.db_date, count(o.OrderId) as Orders 
from time_dimension td 
    left join Orders o 
    on date(o.OrderDate) = db_date 
where td.db_date >= date(adddate(curdate(), interval -30 day)) 
    and td.db_date <= date(curdate()) 
group by td.db_date 

MySQL的日历表参考

• MYSQL: Generate Calendar Table - bryhal (gist)
• Calendar Tables: An Invaluable Database Tool - Brian Showalter

Answer 4

尝试 -

SELECT dateDuringPeriod, SUM(orderValue), COUNT(orderID) 
FROM 
(
    SELECT dateDuringPeriod, 
      IFNULL(orderID, 0) orderID, 
      IFNULL(orderValue, 0) orderValue 
    FROM 
    (
     SELECT DATE_ADD(CURDATE(), INTERVAL singles + tens DAY) dateDuringPeriod 
     FROM 
     (
      SELECT 0 singles 
      UNION ALL SELECT -1 
      UNION ALL SELECT -2 
      UNION ALL SELECT -3 
      UNION ALL SELECT -4 
      UNION ALL SELECT -5 
      UNION ALL SELECT -6 
      UNION ALL SELECT -7 
      UNION ALL SELECT -8 
      UNION ALL SELECT -9 
     ) singles JOIN 
     (
      SELECT 0 tens 
      UNION ALL SELECT -10 
      UNION ALL SELECT -20 
     ) tens 
    ) datesDuringPeriod LEFT JOIN 
    (
     SELECT orderID, 
       DATE(orderDate) orderDate, 
       orderValue 
     FROM tblOrders 
    ) ordersWithoutTimes 
ON datesDuringPeriod.dateDuringPeriod = ordersWithoutTimes.orderDate 
) tblOrderSummary 
GROUP BY dateDuringPeriod 
ORDER BY dateDuringPeriod; 

我已经创建了一个示例表样本DAT a并且发现这个代码是有效的。