Question

付款

Year     Month       Division       Department   Payments_received_Count
------------------------------------------------------------------------
2016       1           Electric      dep1         2
2016       1           Electric      dep2         3
2015       1           Electric      dep1         1

司

Division             Department   
--------------------------------
Electric             Dep1                      
Electric             Dep2                 
Electric             Dep3

如何加入表格以获得以下结果？

Year     Month       Division       Department   Payments_received_Count
------------------------------------------------------------------------
2016       1           Electric      dep1         2
2016       1           Electric      dep2         3
2016       1           Electric      dep3         0
2015       1           Electric      dep1         1
2015       1           Electric      dep2         0
2015       1           Electric      dep3         0

因此，对于每年和每月，我必须使用分部表加入付款表。请提出一个方法。

我知道CASE WHEN会在这种情况下有所帮助，但我找不到正确的方法。

CASE Payments_received_Count
     WHEN null THEN 0
     ELSE Payments_received_Count

由于

Answer 1

您需要部门/部门和年/月的组合。首先，使用ScrollArea生成行。然后使用cross join获取值：

left join

SQL如何在以下场景中连接两个表以获取记录？

1 个答案: