按日期和时间加入范围

Question

我有两个表：

1. 发票
2. 成本

我想找到发票记录创建保证金报告相关的成本记录。

例如，从发票表订单1004，我想从该文件中获取日期和时间，并根据该日期和时间（等于或小于）找到成本。

为了1004 04/15时间的171543这将维成本表记录日期04/15和时间的下方171523.

查看图像的详细信息我怎么会喜欢看的输出。

在此先感谢

发票文件

Order1 Item1 Sales1  Date1 Time1 
1001  | A1001 | 10.00  |04/15 |151025 
1002  | A1001 | 12.00  |04/15 |151112 
1003  | A1001 | 11.00  |04/15 |171235 
1004  | A1001 | 14.00  |04/15 |171543 
1005  | A1001 | 13.50  |04/15 |171855 

---

成本文件

Item2 Cost2 Date2 Time2 
A1001 | 3.50 |04/14 |171255 
A1001 | 4.20 |04/15 |151233 
A1001 | 2.50 |04/15 |171523 
A1001 | 4.00 |04/15 |171623 

---

输出布局 - 保证金报告

Order |Item |Sales  |Cost |Margin 
1001 |A1001 |10.00  |3.50 | 6.50 
1002 |A1001 |12.00  |3.50 | 8.50 
1003 |A1001 |11.00  |2.50 | 8.50 
1004 |A1001 |14.00  |2.50 | 11.50 
1005 |A1001 |13.50  |4.00 | 9.50 

Answer 1

这应该工作

select yourFields 
    from invoice 
     inner join cost on cost.item2 = invoice.item1 
         and cost.date2 = invoice.date1 
         and cost.time2 = (select max(cost_inner.time2) 
              from cost as cost_inner 
             where cost_inner.item2 = invoice.item1 
              and cost_inner.date2 = invoice.date1 
              and cost_inner.time2 <= invoice.time1) 

还有就是要避免内部有更复杂的查询加盟的方式，你可以检查出here