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我试图在MySQL中实现一个系统来存储分层数据。我已决定使用系统实施here，如Bill Karwin所述，从第40张幻灯片开始。我试图设置数据库，以便自动维护EntryPaths表。MySQL分层数据帮助 - 关闭表方法
更新：我已经更新了数据库创建SQL一点。我认为，我已经有1/2的工作要做更新了。运行数据库创建SQL尝试以下
首先看到这个条目的样子后
-- Example query to return a full library entry (0x02 is the entry iD)
SELECT `Library`.* FROM `Library`
LEFT JOIN `EntryPaths` ON `Library`.`iD` = `EntryPaths`.`descendant`
WHERE `EntryPaths`.`ancestor` = 0x02
ORDER BY `Library`.`subsectionOf`, `Library`.`subsectionOrder`
而这一次的外观
-- Example query to return a full library entry (0x08 is the entry iD)
SELECT `Library`.* FROM `Library`
LEFT JOIN `EntryPaths` ON `Library`.`iD` = `EntryPaths`.`descendant`
WHERE `EntryPaths`.`ancestor` = 0x08
ORDER BY `Library`.`subsectionOf`, `Library`.`subsectionOrder`
观看第1项有几个孩子，第二个有没有儿童。运行下面的更新到“大学时光”节点（及其子女）重新设置父级，以John Doe
UPDATE `Library` SET `subsectionOf` = 0x08 WHERE `Library`.`iD` = 0x04;
如果再次运行上面的两个SELECT语句，你会看到，项目已被从Jane Doe删除，但他们有未按预期添加到John Doe。 Library_Update触发器有问题，但我想尽办法解决它。
数据库中创建SQL样本数据：
-- MYSQL
SET FOREIGN_KEY_CHECKS=0;
DROP TRIGGER IF EXISTS Library_Insert;
DROP TRIGGER IF EXISTS Library_Update;
DROP TABLE IF EXISTS Users;
DROP TABLE IF EXISTS Attributes;
DROP TABLE IF EXISTS LibraryHistory;
DROP TABLE IF EXISTS EntryPaths;
DROP TABLE IF EXISTS Library;
SET FOREIGN_KEY_CHECKS=1;
CREATE TABLE `Users` (
`iD` VARBINARY(16) NOT NULL, -- UUID & PK
`libraryID` VARBINARY(16), -- Library UUID & FK (The library entry for this person)
`email` NVARCHAR(255) NOT NULL, -- Email address
`nickname` NVARCHAR(255) NOT NULL, -- Nickname used for display
`firstname` NVARCHAR(255), -- Real first name
`lastname` NVARCHAR(255), -- Real last name
`joinDate` DATETIME NOT NULL, -- Date the account was created
PRIMARY KEY (`iD`)
) ENGINE = MYISAM;
CREATE TABLE `Library` (
`iD` VARBINARY(16) NOT NULL, -- UUID & PK
`name` NVARCHAR(500) NOT NULL, -- Name for the entry
`contentType` NVARCHAR(50) NOT NULL, -- Mime type of data
`content` LONGBLOB NOT NULL, -- Data a for the entry
`subsectionOf` VARBINARY(16), -- Library UUID & FK
`subsectionOrder` INT, -- Oder of Subsections
`lastModifiedBy` VARBINARY(16), -- User UUID & FK
`lastModified` DATETIME NOT NULL, -- Last time the record was updated
PRIMARY KEY (`iD`),
FOREIGN KEY (`subsectionOf`) REFERENCES Library(`iD`) ON DELETE CASCADE,
FOREIGN KEY (`lastModifiedBy`) REFERENCES Users(`iD`),
INDEX(`name`)
) ENGINE = MYISAM;
-- Trigger to update the EntryPaths table for new entries
DELIMITER //
CREATE TRIGGER `Library_Insert` AFTER INSERT ON `Library` FOR EACH ROW
BEGIN
INSERT INTO `EntryPaths` (`ancestor`, `descendant`, `len`)
SELECT `ancestor`, NEW.`iD`, len + 1 FROM `EntryPaths`
WHERE `descendant` = NEW.`subsectionOf`
UNION ALL SELECT NEW.`iD`, NEW.`iD`, 0;
END; //
DELIMITER ;
DELIMITER //
CREATE TRIGGER `Library_Update` BEFORE UPDATE ON `Library` FOR EACH ROW
BEGIN
-- Add the old entry into the history table
INSERT INTO `LibraryHistory` VALUES(UNHEX(REPLACE(UUID(),'-','')),
OLD.`iD`, OLD.`name`, OLD.`contentType`, OLD.`content`,
OLD.`subsectionOf`, OLD.`subsectionOrder`, OLD.`lastModifiedBy`,
OLD.`lastModified`);
-- From http://www.mysqlperformanceblog.com/2011/02/14/moving-subtrees-in-closure-table/
IF OLD.`subsectionOf` != NEW.`subsectionOf` THEN
-- Remove the node from its current parent
DELETE a FROM `EntryPaths` AS a
JOIN `EntryPaths` AS d ON a.`descendant` = d.`descendant`
LEFT JOIN `EntryPaths` AS x
ON x.`ancestor` = d.`ancestor` AND x.`descendant` = a.`ancestor`
WHERE d.`ancestor` = OLD.`iD` AND x.`ancestor` IS NULL;
-- Add the node to its new parent
-- FIXME: Not Working yet
INSERT `EntryPaths` (`ancestor`, `descendant`, `len`)
SELECT supertree.`ancestor`, subtree.`descendant`, supertree.`len`+subtree.`len`+1
FROM `EntryPaths` AS supertree JOIN `EntryPaths` AS subtree
WHERE subtree.`ancestor` = NEW.`iD`
AND supertree.`descendant` = NEW.`subsectionOf`;
END IF;
END; //
DELIMITER ;
CREATE TABLE `EntryPaths` (
`ancestor` VARBINARY(16) NOT NULL,
`descendant` VARBINARY(16) NOT NULL,
`len` VARBINARY(16) NOT NULL,
PRIMARY KEY (`ancestor`, `descendant`),
FOREIGN KEY (`ancestor`) REFERENCES Library(`iD`) ON DELETE CASCADE,
FOREIGN KEY (`descendant`) REFERENCES Library(`iD`) ON DELETE CASCADE
) ENGINE = MYISAM;
CREATE TABLE `LibraryHistory` (
`iD` VARBINARY(16) NOT NULL, -- UUID & PK
`libraryID` VARBINARY(16) NOT NULL, -- Library UUID & FK
`name` NVARCHAR(500) NOT NULL, -- Name for the entry
`contentType` NVARCHAR(50) NOT NULL, -- Mime type of data
`content` LONGBLOB NOT NULL, -- Data a for the entry
`subsectionOf` VARBINARY(16), -- Library UUID & FK
`subsectionOrder` INT, -- Oder of Subsections
`lastModifiedBy` VARBINARY(16), -- User UUID & FK
`lastModified` DATETIME NOT NULL, -- Last time the record was updated
PRIMARY KEY (`iD`),
FOREIGN KEY (`libraryID`) REFERENCES Library(`iD`) ON DELETE CASCADE,
FOREIGN KEY (`lastModifiedBy`) REFERENCES Users(`iD`)
) ENGINE = MYISAM;
CREATE TABLE `Attributes` (
`iD` VARBINARY(16) NOT NULL, -- UUID & PK (Potentially could be removed)
`libraryID` VARBINARY(16) NOT NULL, -- Library UUID & FK
`name` NVARCHAR(500) NOT NULL, -- Name of attribute
`dataType` INT NOT NULL, -- The type of data the attribute holds (int, date, string, etc.)
`data` NVARCHAR(500) NOT NULL, -- Value of attribute
`lastModifiedBy` VARBINARY(16), -- User UUID & FK
`lastModified` DATETIME NOT NULL, -- Last time the record was updated
PRIMARY KEY (`iD`),
FOREIGN KEY (`libraryID`) REFERENCES Library(`iD`) ON DELETE CASCADE,
INDEX (`name`)
) ENGINE = MYISAM;
ALTER TABLE `Users` ADD CONSTRAINT FK_User_Library FOREIGN KEY (`libraryID`) REFERENCES Library(`iD`);
-- Example Data
INSERT INTO `Library` VALUES(0x01, 'People', 'text/plain', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pulvinar scelerisque quam, vel convallis turpis porttitor in. Curabitur pulvinar fermentum pulvinar. Mauris lorem lacus, gravida porta lacinia vitae, dictum ac eros. Aliquam magna arcu, lacinia ac dictum sed, euismod eu elit. Sed semper nulla at velit pulvinar in vehicula risus tempus. Phasellus id nisl libero, id porttitor purus. Integer aliquet semper aliquam. Morbi elit mi, pellentesque et ornare nec, iaculis gravida elit. Sed in luctus lorem. Maecenas a purus at lectus condimentum congue.', NULL, NULL, NULL, '2011-11-16 20:27:54');
INSERT INTO `Library` VALUES(0x02, 'Jane Doe', 'text/x-markup', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pulvinar scelerisque quam, vel convallis turpis porttitor in. Curabitur pulvinar fermentum pulvinar. Mauris lorem lacus, gravida porta lacinia vitae, dictum ac eros. Aliquam magna arcu, lacinia ac dictum sed, euismod eu elit. Sed semper nulla at velit pulvinar in vehicula risus tempus. Phasellus id nisl libero, id porttitor purus. Integer aliquet semper aliquam. Morbi elit mi, pellentesque et ornare nec, iaculis gravida elit. Sed in luctus lorem. Maecenas a purus at lectus condimentum congue.', NULL, NULL, NULL, '2011-11-16 20:29:13');
INSERT INTO `Library` VALUES(0x03, 'Younger Years', 'text/x-markup', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pulvinar scelerisque quam, vel convallis turpis porttitor in. Curabitur pulvinar fermentum pulvinar. Mauris lorem lacus, gravida porta lacinia vitae, dictum ac eros. Aliquam magna arcu, lacinia ac dictum sed, euismod eu elit. Sed semper nulla at velit pulvinar in vehicula risus tempus. Phasellus id nisl libero, id porttitor purus. Integer aliquet semper aliquam. Morbi elit mi, pellentesque et ornare nec, iaculis gravida elit. Sed in luctus lorem. Maecenas a purus at lectus condimentum congue.', 0x02, 1, NULL, '2011-11-16 00:00:00');
INSERT INTO `Library` VALUES(0x04, 'College Years', 'text/x-markup', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pulvinar scelerisque quam, vel convallis turpis porttitor in. Curabitur pulvinar fermentum pulvinar. Mauris lorem lacus, gravida porta lacinia vitae, dictum ac eros. Aliquam magna arcu, lacinia ac dictum sed, euismod eu elit. Sed semper nulla at velit pulvinar in vehicula risus tempus. Phasellus id nisl libero, id porttitor purus. Integer aliquet semper aliquam. Morbi elit mi, pellentesque et ornare nec, iaculis gravida elit. Sed in luctus lorem. Maecenas a purus at lectus condimentum congue.', 0x02, 2, NULL, '2011-11-16 20:31:52');
INSERT INTO `Library` VALUES(0x05, 'Yale', 'text/x-markup', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pulvinar scelerisque quam, vel convallis turpis porttitor in. Curabitur pulvinar fermentum pulvinar. Mauris lorem lacus, gravida porta lacinia vitae, dictum ac eros. Aliquam magna arcu, lacinia ac dictum sed, euismod eu elit. Sed semper nulla at velit pulvinar in vehicula risus tempus. Phasellus id nisl libero, id porttitor purus. Integer aliquet semper aliquam. Morbi elit mi, pellentesque et ornare nec, iaculis gravida elit. Sed in luctus lorem. Maecenas a purus at lectus condimentum congue.', 0x04, 2, NULL, '2011-11-16 20:32:44');
INSERT INTO `Library` VALUES(0x06, 'Old Age', 'text/x-markup', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pulvinar find me here scelerisque quam, vel convallis turpis porttitor in. Curabitur pulvinar fermentum pulvinar. Mauris lorem lacus, gravida porta lacinia vitae, dictum ac eros. Aliquam magna arcu, lacinia ac dictum sed, euismod eu elit. Sed semper nulla at velit pulvinar in vehicula risus tempus. Phasellus id nisl libero, id porttitor purus. Integer aliquet semper aliquam. Morbi elit mi, pellentesque et ornare nec, iaculis gravida elit. Sed in luctus lorem. Maecenas a purus at lectus condimentum congue.', 0x02, 3, NULL, '2011-11-16 20:31:52');
INSERT INTO `Library` VALUES(0x07, 'Community College', 'text/x-markup', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pulvinar scelerisque quam, vel convallis turpis porttitor in. Curabitur pulvinar fermentum pulvinar. Mauris lorem lacus, gravida porta lacinia vitae, dictum ac eros. Aliquam magna arcu, lacinia ac dictum sed, euismod eu elit. Sed semper nulla at velit pulvinar in vehicula risus tempus. Phasellus id nisl libero, id porttitor purus. Integer aliquet semper aliquam. Morbi elit mi, pellentesque et ornare nec, iaculis gravida elit. Sed in luctus lorem. Maecenas a purus at lectus condimentum congue.', 0x04, 1, NULL, '2011-11-16 20:33:11');
INSERT INTO `Library` VALUES(0x08, 'John Doe', 'text/x-markup', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pulvinar scelerisque quam, vel convallis turpis porttitor in. Curabitur pulvinar fermentum pulvinar. Mauris lorem lacus, gravida porta lacinia vitae, dictum ac eros. Aliquam magna arcu, lacinia ac dictum sed, euismod eu elit. Sed semper nulla at velit pulvinar in vehicula risus tempus. Phasellus id nisl libero, id porttitor purus. Integer aliquet semper aliquam. Morbi elit mi, pellentesque et ornare nec, iaculis gravida elit. Sed in luctus lorem. Maecenas a purus at lectus condimentum congue.', NULL, NULL, NULL, '2011-11-16 20:34:40');
INSERT INTO `Library` VALUES(0x09, 'Planets', 'text/x-markup', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pulvinar scelerisque quam, vel convallis turpis porttitor in. Curabitur pulvinar fermentum pulvinar. Mauris lorem lacus, gravida porta lacinia vitae, dictum ac eros. Aliquam magna arcu, lacinia ac dictum sed, euismod eu elit. Sed semper nulla at velit pulvinar in vehicula risus tempus. Phasellus id nisl libero, id porttitor purus. Integer aliquet semper aliquam. Morbi elit mi, pellentesque et ornare nec, iaculis gravida elit. Sed in luctus lorem. Maecenas a purus at lectus condimentum congue.', NULL, NULL, NULL, '2011-11-16 20:27:54');
INSERT INTO `Library` VALUES(0x10, 'Earth', 'text/x-markup', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pulvinar scelerisque quam, vel convallis turpis porttitor in. Curabitur pulvinar fermentum pulvinar. Mauris lorem lacus, gravida porta lacinia vitae, dictum ac eros. Aliquam magna arcu, lacinia ac dictum sed, euismod eu elit. Sed semper nulla at velit pulvinar in vehicula risus tempus. Phasellus id nisl libero, id porttitor purus. Integer aliquet semper aliquam. Morbi elit mi, pellentesque et ornare nec, iaculis gravida elit. Sed in luctus lorem. Maecenas a purus at lectus condimentum congue.', NULL, NULL, NULL, '2011-11-16 20:27:54');
INSERT INTO `Library` VALUES(0x11, 'Mars', 'text/x-markup', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam pulvinar scelerisque quam, vel convallis turpis porttitor in. Curabitur pulvinar fermentum pulvinar. Mauris lorem lacus, gravida porta lacinia vitae, dictum ac eros. Aliquam magna arcu, lacinia ac dictum sed, euismod eu elit. Sed semper nulla at velit pulvinar in vehicula risus tempus. Phasellus id nisl libero, id porttitor purus. Integer aliquet semper aliquam. Morbi elit mi, pellentesque et ornare nec, iaculis gravida elit. Sed in luctus lorem. Maecenas a purus at lectus condimentum congue.', NULL, NULL, NULL, '2011-11-16 20:27:54');
INSERT INTO `Attributes` VALUES(0x01, 0x02, 'TypeOf', 1, 0x01, NULL, '2011-11-16 20:34:40');
INSERT INTO `Attributes` VALUES(0x02, 0x02, 'BirthDate', 2, '19770521', NULL, '2011-11-16 20:34:40');
INSERT INTO `Attributes` VALUES(0x03, 0x02, 'EyeColor', 3, 'Brown', NULL, '2011-11-16 20:34:40');
INSERT INTO `Attributes` VALUES(0x04, 0x08, 'TypeOf', 1, 0x01, NULL, '2011-11-16 20:34:40');
INSERT INTO `Attributes` VALUES(0x05, 0x08, 'BirthDate', 2, '19740521', NULL, '2011-11-16 20:34:40');
INSERT INTO `Attributes` VALUES(0x06, 0x10, 'TypeOf', 1, 0x08, NULL, '2011-11-16 20:34:40');
INSERT INTO `Attributes` VALUES(0x07, 0x11, 'TypeOf', 1, 0x08, NULL, '2011-11-16 20:34:40');
我注意到你的表类型为MYISAM - 但我认为这种类型不支持外键？只是好奇，谢谢张贴。 – dmp