Mysql 递归查询所有子节点，hutool树形结构封装

工作中经常会有像目录，部门的多级结构，记录一下查询自己点的方式，留着复制粘贴

方式1：

SELECT
    * 
FROM
    cus_department 
WHERE
    FIND_IN_SET( id, @pid ) > 0;

UNION

SELECT
    cd.* 
FROM
    ( SELECT * FROM cus_department WHERE pid IS NOT NULL AND deleted = 0 ) cd,
    ( SELECT @pid := '1742370890433187841' ) pd 
WHERE
    FIND_IN_SET( pid, @pid ) > 0 
    AND @pid := concat( @pid, ',', id ) 

UNION 上方包括了自己，只查下级可去掉
需要替换的有
表名：cus_department
查询条件：deleted = 0
父id字段名称：pid
主键名称：id

方式2：

SELECT
    * 
FROM
    (
    SELECT
        c1.*,
    IF
        ( FIND_IN_SET( pid, @parent_ids ) > 0, @parent_ids := CONCAT( @parent_ids, ',', id ), '0' ) AS ischild 
    FROM
        ( SELECT * FROM cus_department AS cd WHERE cd.deleted = 0  ORDER BY cd.id ASC ) c1,
        ( SELECT @parent_ids := '1742370890433187841' ) c2 
    ) c3 
WHERE
    ischild != '0'

此方式只查下级

需要替换的有
表名：cus_department
查询条件：deleted = 0
父id字段名称：pid
主键名称：id

方式3：

	SELECT
	rd.* 
FROM
	( SELECT * FROM cus_department WHERE pid IS NOT NULL AND deleted = 0 ) rd,
	( SELECT @p_id := '1742370890433187841' ) pd 
WHERE
	FIND_IN_SET( pid, @p_id ) > 0 
	AND @p_id := concat( @p_id, ',', id ) 

此方式只查下级
需要替换的有：
表名：cus_department
查询条件：deleted = 0
父id字段名称：pid
主键名称：id

使用hutool快速构建树形结构

引入依赖

<dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.7.17</version>
 </dependency>

代码

      //配置
        TreeNodeConfig treeNodeConfig = new TreeNodeConfig();

        treeNodeConfig.setIdKey("id");
        //设置父类id
        treeNodeConfig.setParentIdKey("pid");
        //设置排序字段
        treeNodeConfig.setWeightKey("orderr");
        //设置树形结构子类
        treeNodeConfig.setChildrenKey("children");

        List<Tree<String>> treesNodes = TreeUtil.build(cusDepartments, "0", treeNodeConfig,
                (result, tree) -> {
                    //设置id
                    tree.setId(String.valueOf(result.getId()));
                    tree.setParentId(String.valueOf(result.getPid()));
                    tree.setName(result.getName());
                    //设置其他字段
                    tree.putExtra("level", result.getLevel());
                    tree.putExtra("createTime",DateUtil.format(result.getCreateTime(), "yyyy-MM-dd"));
                    tree.putExtra("orderr", result.getOrderr());
                });