MySql根据ID查询树结构所有父/子节点

CREATE TABLE `monitor_menu` (
  `id` varchar(45) NOT NULL DEFAULT '0' COMMENT '主键ID',
  `menu_name` varchar(45) DEFAULT NULL COMMENT '名称',
  `parent_id` varchar(45) DEFAULT NULL COMMENT '父级ID',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='树结构数据表';

INSERT INTO `jsbz`.`monitor_menu`(`id`, `menu_name`, `parent_id`) VALUES ('1001', '一级目录', '0');
INSERT INTO `jsbz`.`monitor_menu`(`id`, `menu_name`, `parent_id`) VALUES ('1002', '二级目录1', '1001');
INSERT INTO `jsbz`.`monitor_menu`(`id`, `menu_name`, `parent_id`) VALUES ('1003', '二级目录2', '1001');
INSERT INTO `jsbz`.`monitor_menu`(`id`, `menu_name`, `parent_id`) VALUES ('1004', '二级目录3', '1001');
INSERT INTO `jsbz`.`monitor_menu`(`id`, `menu_name`, `parent_id`) VALUES ('1005', '三级目录1', '1002');
INSERT INTO `jsbz`.`monitor_menu`(`id`, `menu_name`, `parent_id`) VALUES ('1006', '三级目录2', '1003');
INSERT INTO `jsbz`.`monitor_menu`(`id`, `menu_name`, `parent_id`) VALUES ('1007', '三级目录3', '1004');

根据指定ID查询所有子节点数据

DROP FUNCTION IF EXISTS `getChildrenList`;
CREATE FUNCTION `getChildrenList` (rootId VARCHAR ( 1000 )) 
RETURNS VARCHAR ( 1000 ) 
BEGIN
    DECLARE
        sTemp VARCHAR ( 1000 );
    DECLARE
        sTempChd VARCHAR ( 1000 );
    
    SET sTemp = '$';
    SET sTempChd = cast( rootId AS CHAR );
    
    WHILE sTempChd IS NOT NULL DO
        SET sTemp = concat( sTemp, ',', sTempChd );
        SELECT
            group_concat( id ) INTO sTempChd 
        FROM
            monitor_menu 
        WHERE
            FIND_IN_SET( parent_id, sTempChd )> 0;
    END WHILE;
    RETURN sTemp;
END

select * from monitor_menu where FIND_IN_SET(id,getChildrenList('1001'))