MySql行到列（但动态行）

Question

This is my SQL table and data. 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');

Right now it is as,

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

I need to group by relatedId and and get the final output as 1 row for each relatedId.

This is the reference table.

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', '');

The final output should be,

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

The output of phpmyadmin

Answer 1

What you need here is PIVOT rows into columns, MySQL however doesn't have a native pivot operator like SQL Server or Oracle for example. But you can use CASE expression with group by to do this like this:

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;

And to do it dynamically you have to do it with dynamic sql like this:

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;

Note that:

• If the field value is null it will set the value from the default value field, thats what COALESCE(v.fieldValue, f.defaultValue) do.
• You can eliminate NULL values like in the field Aboutname case, by adding a WHERE v.fieldValue IS NOT NULL .

This will give you: