Case When 以不同方式陈述

Question

我需要通过从 MSSQL 中的现有列分配值来创建新列。

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

我想根据commission金额获得commission2栏。情况是这样的

• 如果 CountCustomer=1 那么这很容易。如果佣金<=0 Then commission2 is 0 otherwise equals to commission number.
• 如果 CountCustomer=2（表示一位客户有 2 个品牌），则其中一个佣金金额>0，另一个为 <0 then both commission2 should be the number which is positive. Both of commission numbers are above 0 then these numbers should be stayed same for commission2. If both commission <0 then commission2 should be 0 for both. You can understand more clear from bolded rows on the table above.

谢谢你，

维利

Answer 1

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 2

我使用 https://tableconvert.com/sql-generator 生成 SQL 代码来创建临时表并插入数据。 。然后我将其粘贴到https://sqlfiddle.com/sql-server/online-compiler。现在我们有一个好的起点

CREATE TABLE #tableName 
(
    Customerid  INT,
    CountCustomer   INT,
    Brand   VARCHAR(512),
    commission  INT,
    commission2 VARCHAR(512)
);

INSERT INTO #tableName (Customerid , CountCustomer , Brand , commission , commission2) VALUES ('1000 ', '1 ', 'B ', '-28 ', '0');
INSERT INTO #tableName (Customerid , CountCustomer , Brand , commission , commission2) VALUES ('1001 ', '2 ', 'B ', '12 ', '12');
INSERT INTO #tableName (Customerid , CountCustomer , Brand , commission , commission2) VALUES ('1001 ', '2 ', 'F ', '252 ', '252');
INSERT INTO #tableName (Customerid , CountCustomer , Brand , commission , commission2) VALUES ('1002 ', '1 ', 'B ', '62 ', '62');
INSERT INTO #tableName (Customerid , CountCustomer , Brand , commission , commission2) VALUES ('1003 ', '1 ', 'B ', '5 ', '5');
INSERT INTO #tableName (Customerid , CountCustomer , Brand , commission , commission2) VALUES ('1004 ', '1 ', 'B ', '-61 ', '0');
INSERT INTO #tableName (Customerid , CountCustomer , Brand , commission , commission2) VALUES ('1005 ', '1 ', 'F ', '0 ', '0');
INSERT INTO #tableName (Customerid , CountCustomer , Brand , commission , commission2) VALUES ('1006 ', '1 ', 'F ', '32 ', '32');
INSERT INTO #tableName (Customerid , CountCustomer , Brand , commission , commission2) VALUES ('1007 ', '1 ', 'F ', '0 ', '0');

Select *, 0 as NewColumn from  #tableName