Question

这是我的SQL表和数据。 http://sqlfiddle.com/#!9/effe2

CREATE TABLE IF NOT EXISTS `CustomValue` (
  `id` int(11) NOT NULL,
  `customFieldId` int(11) NOT NULL,
  `relatedId` int(11) NOT NULL,
  `fieldValue` text COLLATE utf8_unicode_ci,
  `createdAt` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP
) ENGINE=MyISAM AUTO_INCREMENT=8 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

INSERT INTO `CustomValue` (`id`, `customFieldId`, `relatedId`, `fieldValue`, `createdAt`) VALUES
(1, 10, 4031, NULL, '2015-11-05 04:25:00'),
(2, 14, 4031, 'adsas@das.sadsa', '2015-11-05 04:25:00'),
(3, 13, 4031, '456', '2015-11-05 04:25:00'),
(4, 16, 4031, '2015-11-09', '2015-11-05 04:25:00'),
(5, 9, 4031, '456', '2015-11-05 04:25:00'),
(6, 11, 4031, 'dsasda', '2015-11-05 04:25:00'),
(7, 15, 4031, '1', '2015-11-05 04:25:00');

现在就是，

id  customFieldId   relatedId   fieldValue         createdAt
1   10                 4031     (null)             November, 05 2015 04:25:00
2   14                 4031     adsas@das.sadsa    November, 05 2015 04:25:00
3   13                 4031     456                November, 05 2015 04:25:00
4   16                 4031     2015-11-09         November, 05 2015 04:25:00
5   9                  4031     456                November, 05 2015 04:25:00
6   11                 4031     dsasda             November, 05 2015 04:25:00
7   15                 4031     1                  November, 05 2015 04:25:00

我需要通过relatedId进行分组，并为每个relatedId获取最终输出为1行。

这是参考表。

CREATE TABLE IF NOT EXISTS `CustomField` (
  `id` int(11) NOT NULL,
  `customTypeId` int(11) NOT NULL,
  `fieldName` varchar(64) COLLATE utf8_unicode_ci DEFAULT NULL,
  `relatedTable` varchar(64) COLLATE utf8_unicode_ci DEFAULT NULL,
  `defaultValue` text COLLATE utf8_unicode_ci,
  `sortOrder` int(11) NOT NULL DEFAULT '0',
  `enabled` char(1) COLLATE utf8_unicode_ci DEFAULT '1',
  `listItemTag` char(1) COLLATE utf8_unicode_ci DEFAULT NULL,
  `required` char(1) COLLATE utf8_unicode_ci DEFAULT '0',
  `onCreate` char(1) COLLATE utf8_unicode_ci DEFAULT '1',
  `onEdit` char(1) COLLATE utf8_unicode_ci DEFAULT '1',
  `onView` char(1) COLLATE utf8_unicode_ci DEFAULT '1',
  `listValues` text COLLATE utf8_unicode_ci,
  `label` varchar(64) COLLATE utf8_unicode_ci DEFAULT NULL,
  `htmlOptions` text COLLATE utf8_unicode_ci
) ENGINE=MyISAM AUTO_INCREMENT=17 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

INSERT INTO `CustomField` (`id`, `customTypeId`, `fieldName`, `relatedTable`, `defaultValue`, `sortOrder`, `enabled`, `listItemTag`, `required`, `onCreate`, `onEdit`, `onView`, `listValues`, `label`, `htmlOptions`) VALUES
(13, 1, 'HOMEEMAIL', 'people', '', 0, '1', NULL, '1', '1', '1', '1', NULL, 'Home Email', ''),
(9, 1, 'LANDPHONENO', 'people', '', 0, '1', NULL, '1', '1', '1', '1', NULL, 'Land Phone No', ''),
(10, 12, 'ABOUTME', 'people', '', 0, '1', NULL, '0', '1', '1', '1', NULL, 'About Me', ''),
(11, 3, 'PHONENUMBER2', 'people', '', 0, '1', NULL, '1', '1', '1', '1', NULL, 'Phone Number 2', ''),
(14, 3, 'ALTERNATEEMAIL', 'people', '', 0, '1', NULL, '1', '1', '1', '1', NULL, 'Alternate Email', ''),
(15, 11, 'SCHOOLING?', 'people', '', 0, '1', NULL, '1', '1', '1', '1', NULL, 'Schooling?', ''),
(16, 4, 'JOINDATE', 'people', '', 0, '1', NULL, '1', '1', '1', '1', NULL, 'Join Date', '');

最终输出应为

relatedId | Alternate Email | Home Email | Join Date | Land Phone No | Phone Number 2 | Schooling?
--------------------------------------------------------------------------------------------------
4031      | adsas@das.sadsa | 456        | 2015-11-09| 456           | dsasda         | 1

relatedId | Alternate Email | Home Email | Join Date | Land Phone No | Phone Number 2 | Schooling? | Interest
--------------------------------------------------------------------------------------------------
4033      | adsas@das.sadsa | 456        | 2015-11-09| 456           | dsasda         | 1 | Drawing

phpmyadmin的输出

Answer 1

这里你需要的是PIVOT行到列，但是MySQL并没有像SQL Server或Oracle这样的本地数据透视运算符。但您可以使用{by CASE表达式与group by一起执行此操作：

SELECT 
  v.relatedId, v.CreatedAt,
  MAX(IF(f.fieldName = 'ABOUTME', COALESCE(v.fieldValue, f.defaultValue) , NULL)) AS 'ABOUTME',
  MAX(IF(f.fieldName = 'ALTERNATEEMAIL', COALESCE(v.fieldValue, f.defaultValue) , NULL)) AS 'ALTERNATEEMAIL',
  MAX(IF(f.fieldName = 'HOMEEMAIL', COALESCE(v.fieldValue, f.defaultValue) , NULL)) AS 'HOMEEMAIL',
  MAX(IF(f.fieldName = 'JOINDATE', COALESCE(v.fieldValue, f.defaultValue) , NULL)) AS 'JOINDATE',
  MAX(IF(f.fieldName = 'LANDPHONENO', COALESCE(v.fieldValue, f.defaultValue) , NULL)) AS 'LANDPHONENO',
  MAX(IF(f.fieldName = 'PHONENUMBER2', COALESCE(v.fieldValue, f.defaultValue) , NULL)) AS 'PHONENUMBER2',
  MAX(IF(f.fieldName = 'SCHOOLING?', COALESCE(v.fieldValue, f.defaultValue) , NULL)) AS 'SCHOOLING?'
FROM customField AS f
INNER JOIN Customvalue AS v ON f.Id = v.customFieldId 
GROUP BY   v.relatedId, v.CreatedAt;

要动态地执行它，你必须使用动态sql这样做：

SET @Colvalues = NULL;
SET @sql = NULL;

SELECT
  GROUP_CONCAT(DISTINCT CONCAT('MAX(IF(f.fieldName = ''',
      f.fieldName, ''', COALESCE(v.fieldValue, f.defaultValue) , NULL)) AS ', '''', f.fieldName , '''')
  ) INTO @Colvalues
FROM customField AS f
INNER JOIN Customvalue AS v ON f.Id = v.customFieldId;


SET @sql = CONCAT('SELECT 
    v.relatedId, v.CreatedAt, ', @Colvalues , '
FROM customField AS f
INNER JOIN Customvalue AS v ON f.Id = v.customFieldId 
GROUP BY   v.relatedId, v.CreatedAt;');

PREPARE stmt 
FROM @sql;

EXECUTE stmt;

请注意：

如果字段值为null，则会设置默认值字段中的值，即COALESCE(v.fieldValue, f.defaultValue)的值。
您可以通过添加NULL来消除Aboutname字段WHERE v.fieldValue IS NOT NULL中的private void btnPostActionPerformed(java.awt.event.ActionEvent evt) { RestTemplate restTemplate = new RestTemplate(); Issuer issuer = new Issuer(); issuer.setCountry("Teacher 1"); issuer.setIssuerName("Department 1"); String url = txtHost.getText()+txtGet.getText(); restTemplate.postForObject(url, issuer, Issuer.class) ; }值。

这会给你：

MySql行到列（但动态行）

1 个答案: