一 表结构
CREATE TABLE `sys_user` (
`id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键',
`parent_id` bigint(255) NOT NULL COMMENT '父节点id',
`hierarchy` varchar(255) DEFAULT NULL COMMENT '层级关系',
`name` varchar(255) NOT NULL COMMENT '用户名',
`password` varchar(255) NOT NULL COMMENT '用户密码',
`enabled` tinyint(255) NOT NULL DEFAULT '1' COMMENT '是否可用(0:停用 1:可用)',
`phone` bigint(255) NOT NULL DEFAULT '0' COMMENT '手机号',
`store_id` bigint(20) DEFAULT NULL COMMENT '门店id',
`create_time` datetime DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '创建时间',
`deleted` tinyint(2) NOT NULL DEFAULT '0' COMMENT '逻辑删(0:未删,1已删)',
`user_type_enums` int(255) DEFAULT NULL COMMENT '角色(1:学员 2:教师 4:班主任)',
PRIMARY KEY (`id`) USING BTREE,
UNIQUE KEY `un_password` (`password`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=13 DEFAULT CHARSET=utf8mb4;
CREATE DEFINER=`root`@`%` TRIGGER `sys_user_hierarchy_triger` BEFORE INSERT ON `sys_user` FOR EACH ROW BEGIN
DECLARE _hierarchy VARCHAR(255);
IF (new.parent_id is not NULL) THEN
SET _hierarchy = (
SELECT hierarchy
FROM sys_user
WHERE id = new.parent_id
);
SET new.hierarchy = CONCAT(_hierarchy, new.parent_id, '/');
ELSE
SET new.hierarchy = '/';
END
IF;
END;
查询子节点的时候
//查询子节点需要加根节点的id 使用likeRight可以利用到索引
IPage<SysUser> page = this.sysUserService.page(new Page<>(pagingVO.getPage(), pagingVO.getLimit()), new LambdaQueryWrapper<SysUser>()
.likeRight(StringUtils.isNotEmpty(vo.getHierarchy()), SysUser::getHierarchy, vo.getHierarchy() + vo.getId())
新增时利用触发器自动维护hierarchy层级字段
触发器为
触发器维护hierarchy
BEGIN
DECLARE _hierarchy VARCHAR(255);
IF (new.parent_id is not NULL) THEN
SET _hierarchy = (
SELECT hierarchy
FROM sys_user
WHERE id = new.parent_id
);
SET new.hierarchy = CONCAT(_hierarchy, new.parent_id, '/');
ELSE
SET new.hierarchy = '/';
END
IF;
END
修改是代码维护改层级hierarchy字段 自己写的模板代码生成
##定义Dao名
#set($daoName = $!tool.append($!tool.firstLowerCase($!tableInfo.name), "Dao"))
/**
* 改变了父节点 所有子节点的层级字段需要维护
*
* @author $!author
* @Date $!time.currTime()
* @param id 节点自己
* @param newParentId 新的父节点
* @return java.lang.Boolean 是否成功
**/
@Override
@Transactional(rollbackFor = Exception.class)
public Boolean updateHierarchy(Long id, Long newParentId) {
//父节点data
$!{tableInfo.name}Entity byId = $tool.append("this.",$daoName,".selectById(id)");
if (Objects.isNull(byId)) {
throw new SZException("修改的数据不存在!");
}
//校验, 修改的父节点不能挂到自己本身
if (byId.getId().equals(newParentId)) {
throw new SZException("不能挂载到本身或本身的子节点!");
}
//查询需要维护的子节点
List<$!{tableInfo.name}Entity> entitys = $tool.append("this.",$daoName,".selectList(new LambdaQueryWrapper<",$!{tableInfo.name},"Entity>()")
.likeRight($!{tableInfo.name}Entity::getHierarchy, byId.getHierarchy() + byId.getId()));
//校验 , 修改的父节点不能是自己的子节点
List<Long> collect = entitys.stream()
.map($!{tableInfo.name}Entity::getId)
.collect(Collectors.toList());
if (collect.contains(newParentId)) {
throw new SZException("不能挂载到本身的子节点!");
}
//旧的父节点
$!{tableInfo.name}Entity oldParent = $tool.append("this.",$daoName,".selectById(byId.getParentId());")
//新的父节点
$!{tableInfo.name}Entity newParent = $tool.append("this.",$daoName,".selectById(newParentId);")
//0是根节点是存在的
if (0 != newParentId) {
if (Objects.isNull(newParent)) {
throw new SZException("挂载的父节点不存在");
}
}
//维护父节点parentId
$!{tableInfo.name}Entity updateParent = new $!{tableInfo.name}Entity();
updateParent.setId(byId.getId());
updateParent.setHierarchy(byId.getHierarchy());
updateParent.setParentId(newParentId);
//维护节点的parentId
$tool.append("this.",$daoName,".update(updateParent, new LambdaUpdateWrapper<",$!{tableInfo.name},"Entity>()")
.eq($!{tableInfo.name}Entity::getId, byId.getId()));
//根节点加入维护hierarchy
entitys.add(updateParent);
//维护节点的所有子节点的hierarchy
entitys.forEach(entity -> {
$!{tableInfo.name}Entity updataEntity = new $!{tableInfo.name}Entity();
String olds ="";
if (!Objects.isNull(oldParent) || byId.getParentId() == 0) {
if (byId.getParentId() == 0) {
olds ="/";
} else {
olds = oldParent.getHierarchy() + oldParent.getId() + "/";
}
}
//旧的Hierarchy去掉父节点以上层级
String s = null;
if (StringUtils.startsWith(entity.getHierarchy(),olds)) {
s = entity.getHierarchy().substring(olds.length());
}
//说明是根节点
if (null == s || "/".equals(s)) {
s = "";
}
//根节点没有id = 0的节点
if (Objects.isNull(newParent)) {
updataEntity.setHierarchy("/" + s);
} else {
updataEntity.setHierarchy(newParent.getHierarchy() + newParent.getId() + "/" + s);
}
//更新需要维护的hierarchy
$tool.append("this.",$daoName,".update(updataEntity, new LambdaUpdateWrapper<",$!{tableInfo.name},"Entity>()")
.eq($!{tableInfo.name}Entity::getId, entity.getId()));
});
return true;
}
/**
* 获取该节点的所有父节点
* @author $!author
* @Date $!time.currTime()
* @return java.util.List<java.lang.Long> 父节点集合
**/
List<Long> getParentIds(String hierarchy) {
return Arrays.stream(hierarchy.split("/"))
.filter(StringUtils::isNotBlank)
.map(Long::parseLong)
.collect(Collectors.toList());
}
/** 限制层级最多为10
int hierarchyDeep = getHierarchyDeep(byId.getHierarchy());
if (hierarchyDeep == 10) {
return Result.error("最多挂载10层,无法继续挂载子节点");
}
**/
/**
* 根据树路径获取层级
* @author $!author
* @Date $!time.currTime()
* @return 层级
*/
private int getHierarchyDeep(String hierarchy) {
return (int) (Arrays.stream(hierarchy.split("/"))
.filter(StringUtils::isNotBlank).count() + 1);
}
在sql里面获取一些层级关系
# 获取id=5的层级关系 result:/1/2/3/4/ 图一
select hierarchy from sys_user where id = 5;
# 转换获取层级 result:,1,2,3,4, 图二
select replace((select hierarchy from sys_user where id = 5), '/', ',');
# 切割首尾逗号 result:1,2,3,4 图三
SELECT trim(BOTH ',' FROM (select replace((select hierarchy from sys_user where id = 5), '/', ','))) as str;
# 利用mysql自带help_topic进行字符串转行结构 图四
SELECT DISTINCT substring_index(substring_index(a.str, ',', b.help_topic_id + 1), ',', - 1)
FROM (SELECT trim(BOTH ',' FROM (select replace((select hierarchy from sys_user where id = 5), '/', ','))) as str) a
INNER JOIN mysql.help_topic b
ON b.help_topic_id < (length(a.str) - length(replace(a.str, ',', '')) + 1);
# 获取所有父节点数据 图五
select *
from sys_user
where id in (
SELECT DISTINCT substring_index(substring_index(a.str, ',', b.help_topic_id + 1), ',', - 1)
FROM (SELECT trim(BOTH ',' FROM (select replace((select hierarchy from sys_user where id = 5), '/', ','))) as str) a
INNER JOIN mysql.help_topic b
ON b.help_topic_id < (length(a.str) - length(replace(a.str, ',', '')) + 1)
)
下面的sql 是看到做的笔记, 和维护层级树不相关(不相关的sql , GROUP_CONCAT收集结果集)
# xxx:yjx2,xxx11:yjx3,xxx3:yjx4,xxx4:yjx5,xxx5:yjx6,xxx6:yjx7
select GROUP_CONCAT(name, ':', password)
from sys_user
where name like 'xx%';
#获取ids 2,3,4,5,6,7
select GROUP_CONCAT(id) as str
from sys_user
where name like 'xx%';
# 使用获取的ids获取行
select *
from sys_user
where id in (
SELECT DISTINCT substring_index(substring_index(a.str, ',', b.help_topic_id + 1), ',', - 1)
FROM (select GROUP_CONCAT(id) as str from sys_user where name like 'xx%') a
INNER JOIN mysql.help_topic b
ON b.help_topic_id < (length(a.str) - length(replace(a.str, ',', '')) + 1));
图一 : 获取id=5的层级关系 result:/1/2/3/4/
图二 : 转换获取层级 result:,1,2,3,4,
图三 : 切割首尾逗号 result:1,2,3,4
图四 : 利用mysql自带help_topic进行字符串转行结构
图五 : 获取所有父节点数据
