不同表达方式的情况

Question

我需要通过从 SQL Server 中的现有列分配值来创建新列。

我想根据

commission2

金额获取

commission

列。

有些客户可以包含1或2个品牌和佣金金额。

客户编号	计数客户	品牌	佣金	佣金2
1000	1	B	-28	0
1001	2	B	12	12
1001	2	F	252	252
1002	1	B	62	62
1003	1	B	5	5
1004	1	B	-61	0
1005	1	F	0	0
1006	1	F	32	32
1007	1	F	0	0
1008	1	B	-496	0
1009	1	F	1	1
1010	1	B	1	1
1011	1	B	0	0
1012	1	F	-10	0
1013	1	B	82	82
1014	1	B	54	54
1015	1	B	18	18
1016	1	B	0	0
1017	2	B	0	0
1017	2	F	-21	0
1018	1	B	0	0
1019	1	B	5	5
1020	1	B	-3	0
1021	1	F	-1	0
1022	1	B	95	95
1023	1	B	-20	0
1024	1	B	0	0
1025	2	B	-65	10
1025	2	F	10	10
1026	2	B	24	24
1026	2	F	-7	24
1027	2	B	0	0
1027	2	F	0	0

规则如下：

"

• 如果

  CountCustomer = 1

  那就很� 75e1 ��易了。"如果

  commission <= 0

  则

  commission2

  为 0，否则等于

  commission

• 如果

  CountCustomer = 2

  （表示客户有2个品牌），且其中一个佣金金额> 0，而另一个为< 0, then both

  commission2

  ，则值应为正数。如果两个佣金数字都高于 0，那么这些数字在

  commission2

  期间应保持不变。如果两个佣金都是 < 0 then commission2 should be 0 for both. You can understand more clear from bolded rows on the table above.

Answer 1

使用窗口函数查看每个客户的条目数量以及最小和最大佣金：

select 
  customerid,
  count(*) over (partition by customerid) as countcustomer,
  brand,
  commission,
  case 
    when count(*) over (partition by customerid) = 1 then
      case when commission < 0 then 0 else commission end
    else
      case 
        when max(commission) (partition by customerid) <= 0 then
          0
        when min(commission) (partition by customerid) >  0 then
          commission
        else
          max(commission) (partition by customerid)
      end
  end as commission2
from mytable
order by customerid, brand;

或者，由于多行条件也适用于单行客户，因此：

select 
  customerid,
  count(*) over (partition by customerid) as countcustomer,
  brand,
  commission,
  case 
    when max(commission) (partition by customerid) <= 0 then
      0
    when min(commission) (partition by customerid) >  0 then
      commission
    else
      max(commission) (partition by customerid)
  end as commission2
from mytable
order by customerid, brand;

Answer 2

我不认为这是你正在寻找的逻辑，但如果这是我的理解，那么 CASE WHEN 应该是这样的：

SELECT Customerid, CountCustomer, Brand, comission,
         CASE WHEN CountCustomer = 1 AND commission > 0 THEN commision
            WHEN CountCustomer = 1 AND commission < 0 THEN 0
            WHEN CountCustomer = 2 AND commission > 0 THEN comission
            WHEN CountCustomer = 2 AND commission < 0 THEN 0
            END AS commission2
FROM YourTable

Answer 3

SELECT
    Customerid  
    ,CountCustomer  
    ,Brand  
    ,commission
    CASE WHEN CountCustomer = 1 AND commission >= 0 THEN commission
         WHEN CountCustomer = 2 AND commission > 0 AND commission2 < 0 THEN commission
         WHEN CountCustomer = 2 AND commission < 0 AND commission2 > 0 THEN commission2
         WHEN CountCustomer = 2 AND commission < 0 AND commission2 < 0 THEN 0   
    ELSE commission2 AS 'commission2'
FROM MyTable

我尽力听从你的解释。您可以根据需要修改这些语句。这应该按照您的需要返回列 commission2。

Answer 4

这将处理所提出的案例：

max(case when commission < 0 then 0 else commission end) over (partition by customerid)

如果这种情况可能的话，它将返回两个正值中较大的一个。