mysql - 一个字段的值基于另一个字段的总和

Question

我有一个表格如下。我需要构建一个查询来查找以下内容。

( FeeComponentValue Sum 的 where feeComponentCalc = 1 ) - ( FeeComponentValue Sum 的 where feeComponentCalc = 1 ) 应该是 group by feeSettingId

请帮忙

CREATE TABLE `feevalues` (
  `feevaluesId` int(11) NOT NULL,
  `feeSettingId` int(11) NOT NULL,
  `feeComponentId` int(11) NOT NULL,
  `feeComponentValue` int(11) DEFAULT NULL,
  `feeComponentCalc` int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

--

--转储表feevalues的数据

INSERT INTO `feevalues`
(`feevaluesId`, `feeSettingId`, `feeComponentId`, `feeComponentValue`, `feeComponentCalc`) 
VALUES
(27, 29, 1, 1000, 1),
(28, 29, 12, 2000, 1),
(29, 29, 3, 3000, 1),
(30, 29, 4, 4000, 1),
(103, 30, 3, 1000, 1),
(104, 30, 1, 2000, 1),
(105, 30, 3, 3000, 1),
(106, 30, 1, 4000, 1),
(107, 30, 14, 5000, 2),
(108, 30, 2, 6000, 2),
(109, 30, 13, 7000, 2),
(110, 30, 2, 8000, 2),
(111, 31, 1, 1000, 1),
(112, 31, 3, 2000, 1),
(113, 31, 13, 4000, 2),
(114, 31, 2, 3000, 2),
(122, 32, 1, 1, 1),
(123, 32, 3, 3, 1),
(124, 32, 4, 4, 1),
(125, 32, 2, 5, 2),
(126, 32, 14, 6, 2),
(127, 32, 13, 7, 2);

--

Answer 1

我假设您的意思是在第二种情况下...其中 FeeComponentCalc = 2...，对吗？
使用条件聚合:

select 
  feeSettingId,
  sum(case feeComponentCalc when 1 then feeComponentValue else 0 end) -
  sum(case feeComponentCalc when 2 then feeComponentValue else 0 end) as result
from feevalues
group by feeSettingId

请参阅demo .
或者:

select 
  feeSettingId,
  sum(
    case feeComponentCalc 
      when 1 then feeComponentValue 
      when 2 then -feeComponentValue
      else 0 
    end
  ) as result
from feevalues
group by feeSettingId

请参阅demo .
结果:

| feeSettingId | result |
| ------------ | ------ |
| 29           | 10000  |
| 30           | -16000 |
| 31           | -4000  |
| 32           | -10    |