次の MySQL 構造は問題なく正規化されるはずです。場合によっては、クエリの記述が少し複雑になりますが、アプリケーションがより強力になり、パフォーマンスに影響を与えることなく指数関数的に成長できるようになります。私たちは、さまざまなインタビュー、メモ、その他のデータへの外部キーを保持する多くの関連テーブルを備えた大規模な MySQL データベースを持っています。グループをテーブル名として使用する場合は、次のような `` マークを忘れずに使用してください。
`group`
INNER JOIN group ON (foo=bar)
そうすれば、MySQL は aと expectを無効にしようとしませんGROUP BY
。また、アプリケーションのフロント エンドに制限を設けて、親なしでデバイスが追加されるのを防ぐ必要があります。しかし、それを行うのはそれほど難しいことではありません。とにかく、例を見て、実験/プログラミングを楽しんでください!
オンライン デモ: http://www.sqlfiddle.com/#!2/e9e94/2/0
質問から必要な各ケースの 1 つのインスタンスを説明する最小量のデータを含む提案された MySQL テーブル構造を次に示します。コピーして .sql ファイルに貼り付け、phpMyAdmin を使用して空のデータベースにインポートします。
-- phpMyAdmin SQL Dump
-- version 3.5.2.2
-- http://www.phpmyadmin.net
--
-- Host: 127.0.0.1
-- Generation Time: Jun 07, 2013 at 08:14 PM
-- Server version: 5.5.27
-- PHP Version: 5.4.7
SET FOREIGN_KEY_CHECKS=0;
SET SQL_MODE="NO_AUTO_VALUE_ON_ZERO";
SET time_zone = "+00:00";
/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;
--
-- Database: `stackoverflow`
--
-- --------------------------------------------------------
--
-- Table structure for table `device`
--
CREATE TABLE IF NOT EXISTS `device` (
`id` int(11) NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=7 ;
--
-- Dumping data for table `device`
--
INSERT INTO `device` (`id`) VALUES
(1),
(2),
(3),
(4),
(5),
(6);
-- --------------------------------------------------------
--
-- Table structure for table `group`
--
CREATE TABLE IF NOT EXISTS `group` (
`id` int(11) NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=9 ;
--
-- Dumping data for table `group`
--
INSERT INTO `group` (`id`) VALUES
(1),
(2),
(3),
(4),
(5),
(6),
(7),
(8);
-- --------------------------------------------------------
--
-- Table structure for table `groups_have_devices`
--
CREATE TABLE IF NOT EXISTS `groups_have_devices` (
`group_id` int(11) NOT NULL,
`device_id` int(11) NOT NULL,
PRIMARY KEY (`group_id`,`device_id`),
KEY `device_id` (`device_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
--
-- Dumping data for table `groups_have_devices`
--
INSERT INTO `groups_have_devices` (`group_id`, `device_id`) VALUES
(4, 6);
-- --------------------------------------------------------
--
-- Table structure for table `groups_have_people`
--
CREATE TABLE IF NOT EXISTS `groups_have_people` (
`group_id` int(11) NOT NULL,
`person_id` int(11) NOT NULL,
PRIMARY KEY (`group_id`,`person_id`),
KEY `person_id` (`person_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
--
-- Dumping data for table `groups_have_people`
--
INSERT INTO `groups_have_people` (`group_id`, `person_id`) VALUES
(1, 2),
(5, 5);
-- --------------------------------------------------------
--
-- Table structure for table `groups_have_sites`
--
CREATE TABLE IF NOT EXISTS `groups_have_sites` (
`group_id` int(11) NOT NULL,
`site_id` int(11) NOT NULL,
PRIMARY KEY (`group_id`,`site_id`),
KEY `site_id` (`site_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
--
-- Dumping data for table `groups_have_sites`
--
INSERT INTO `groups_have_sites` (`group_id`, `site_id`) VALUES
(2, 2),
(3, 4),
(6, 6),
(7, 8);
-- --------------------------------------------------------
--
-- Table structure for table `people_have_devices`
--
CREATE TABLE IF NOT EXISTS `people_have_devices` (
`person_id` int(11) NOT NULL,
`device_id` int(11) NOT NULL,
PRIMARY KEY (`person_id`,`device_id`),
KEY `device_id` (`device_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
--
-- Dumping data for table `people_have_devices`
--
INSERT INTO `people_have_devices` (`person_id`, `device_id`) VALUES
(1, 1),
(2, 2),
(3, 3);
-- --------------------------------------------------------
--
-- Table structure for table `person`
--
CREATE TABLE IF NOT EXISTS `person` (
`id` int(11) NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=7 ;
--
-- Dumping data for table `person`
--
INSERT INTO `person` (`id`) VALUES
(1),
(2),
(3),
(4),
(5),
(6);
-- --------------------------------------------------------
--
-- Table structure for table `site`
--
CREATE TABLE IF NOT EXISTS `site` (
`id` int(11) NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=9 ;
--
-- Dumping data for table `site`
--
INSERT INTO `site` (`id`) VALUES
(1),
(2),
(3),
(4),
(5),
(6),
(7),
(8);
-- --------------------------------------------------------
--
-- Table structure for table `sites_have_devices`
--
CREATE TABLE IF NOT EXISTS `sites_have_devices` (
`site_id` int(11) NOT NULL,
`device_id` int(11) NOT NULL,
PRIMARY KEY (`site_id`,`device_id`),
KEY `device_id` (`device_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
--
-- Dumping data for table `sites_have_devices`
--
INSERT INTO `sites_have_devices` (`site_id`, `device_id`) VALUES
(3, 4),
(4, 5);
-- --------------------------------------------------------
--
-- Table structure for table `sites_have_people`
--
CREATE TABLE IF NOT EXISTS `sites_have_people` (
`site_id` int(11) NOT NULL,
`person_id` int(11) NOT NULL,
PRIMARY KEY (`site_id`,`person_id`),
KEY `person_id` (`person_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
--
-- Dumping data for table `sites_have_people`
--
INSERT INTO `sites_have_people` (`site_id`, `person_id`) VALUES
(1, 1),
(2, 3),
(5, 4),
(6, 6);
--
-- Constraints for dumped tables
--
--
-- Constraints for table `groups_have_devices`
--
ALTER TABLE `groups_have_devices`
ADD CONSTRAINT `groups_have_devices_ibfk_2` FOREIGN KEY (`device_id`) REFERENCES `device` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION,
ADD CONSTRAINT `groups_have_devices_ibfk_1` FOREIGN KEY (`group_id`) REFERENCES `group` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION;
--
-- Constraints for table `groups_have_people`
--
ALTER TABLE `groups_have_people`
ADD CONSTRAINT `groups_have_people_ibfk_2` FOREIGN KEY (`person_id`) REFERENCES `person` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION,
ADD CONSTRAINT `groups_have_people_ibfk_1` FOREIGN KEY (`group_id`) REFERENCES `group` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION;
--
-- Constraints for table `groups_have_sites`
--
ALTER TABLE `groups_have_sites`
ADD CONSTRAINT `groups_have_sites_ibfk_2` FOREIGN KEY (`site_id`) REFERENCES `site` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION,
ADD CONSTRAINT `groups_have_sites_ibfk_1` FOREIGN KEY (`group_id`) REFERENCES `group` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION;
--
-- Constraints for table `people_have_devices`
--
ALTER TABLE `people_have_devices`
ADD CONSTRAINT `people_have_devices_ibfk_2` FOREIGN KEY (`device_id`) REFERENCES `device` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION,
ADD CONSTRAINT `people_have_devices_ibfk_1` FOREIGN KEY (`person_id`) REFERENCES `person` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION;
--
-- Constraints for table `sites_have_devices`
--
ALTER TABLE `sites_have_devices`
ADD CONSTRAINT `sites_have_devices_ibfk_2` FOREIGN KEY (`device_id`) REFERENCES `device` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION,
ADD CONSTRAINT `sites_have_devices_ibfk_1` FOREIGN KEY (`site_id`) REFERENCES `site` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION;
--
-- Constraints for table `sites_have_people`
--
ALTER TABLE `sites_have_people`
ADD CONSTRAINT `sites_have_people_ibfk_2` FOREIGN KEY (`person_id`) REFERENCES `person` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION,
ADD CONSTRAINT `sites_have_people_ibfk_1` FOREIGN KEY (`site_id`) REFERENCES `site` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION;
SET FOREIGN_KEY_CHECKS=1;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
すべてのグループのすべての子デバイスを検索するクエリを次に示します。
SELECT
`group`.`id` AS `group_id`,
`device`.`id` AS `device_id`
FROM
`group`
INNER JOIN groups_have_devices
ON (group.id=groups_have_devices.group_id)
INNER JOIN device
ON (groups_have_devices.device_id=device.id)
UNION ALL
SELECT
`group`.`id` AS `group_id`,
`device`.`id` AS `device_id`
FROM
`group`
INNER JOIN groups_have_people
ON (group.id=groups_have_people.group_id)
INNER JOIN person
ON (groups_have_people.person_id=person.id)
INNER JOIN people_have_devices
ON (person.id=people_have_devices.person_id)
INNER JOIN device
ON (people_have_devices.device_id=device.id)
UNION ALL
SELECT
`group`.`id` AS `group_id`,
`device`.`id` AS `device_id`
FROM
`group`
INNER JOIN groups_have_sites
ON (group.id=groups_have_sites.group_id)
INNER JOIN site
ON (groups_have_sites.site_id=site.id)
INNER JOIN sites_have_devices
ON (site.id=sites_have_devices.site_id)
INNER JOIN device
ON (sites_have_devices.device_id=device.id)
UNION ALL
SELECT
`group`.`id` AS `group_id`,
`device`.`id` AS `device_id`
FROM
`group`
INNER JOIN groups_have_sites
ON (group.id=groups_have_sites.group_id)
INNER JOIN site
ON (groups_have_sites.site_id=site.id)
INNER JOIN sites_have_people
ON (site.id=sites_have_people.site_id)
INNER JOIN person
ON (sites_have_people.person_id=person.id)
INNER JOIN people_have_devices
ON (person.id=people_have_devices.person_id)
INNER JOIN device
ON (people_have_devices.device_id=device.id)
ORDER BY
group_id
次に、すべてのデバイスとその直接の親を取得するクエリを示します。
SELECT
device.id AS device_id,
person.id AS person_id,
NULL AS site_id,
NULL AS group_id
FROM
device
INNER JOIN people_have_devices
ON (device.id=people_have_devices.device_id)
INNER JOIN person
ON (people_have_devices.person_id=person.id)
UNION ALL
SELECT
device.id AS device_id,
NULL AS person_id,
site.id AS site_id,
NULL AS group_id
FROM
device
INNER JOIN sites_have_devices
ON (device.id=sites_have_devices.device_id)
INNER JOIN site
ON (sites_have_devices.site_id=site.id)
UNION ALL
SELECT
device.id AS device_id,
NULL AS person_id,
NULL AS site_id,
group.id AS group_id
FROM
device
INNER JOIN groups_have_devices
ON (device.id=groups_have_devices.device_id)
INNER JOIN `group`
ON (groups_have_devices.group_id=group.id)
このように、特定の人、グループ、またはサイトの直接の子であるデバイスをさらに取得できます
SELECT
device_id
FROM (
SELECT
device.id AS device_id,
NULL AS person_id,
site.id AS site_id,
NULL AS group_id
FROM
device
INNER JOIN sites_have_devices
ON (device.id=sites_have_devices.device_id)
INNER JOIN site
ON (sites_have_devices.site_id=site.id)
) sub_query
WHERE
sub_query.site_id='3'