MySQL如何查找树形结构中某个节点及其子节点

create table test
(
    id           varchar(30) collate utf8mb4_general_ci default '' not null
        primary key,
    name         varchar(100) collate utf8mb4_general_ci           null,
    parentId     varchar(30) collate utf8mb4_general_ci            null comment '父分类id'
)
    comment 'test';

select GROUP_CONCAT(id) from (SELECT @ids as id,
                                      (SELECT @ids := GROUP_CONCAT(id) FROM test
                                       WHERE FIND_IN_SET(parentId, CONVERT(@ids USING utf8mb4) COLLATE utf8mb4_0900_ai_ci)
                                      ) AS childrenId
                               FROM test, (SELECT @ids := '节点id') var
                                WHERE @ids IS NOT NULL) t

SELECT GROUP_CONCAT(id)  FROM
    (SELECT @id AS id,
            (SELECT @id := parentId FROM test WHERE id = CONVERT(@id USING utf8mb4) COLLATE utf8mb4_0900_ai_ci) AS pid
     FROM test, ( SELECT @id := '节点id') var WHERE @id IS NOT NULL) t

create table test
(
    id           varchar(30) collate utf8mb4_general_ci default '' not null
        primary key,
    name         varchar(100) collate utf8mb4_general_ci           null,
    parentId     varchar(30) collate utf8mb4_general_ci            null comment '父分类id',
    path         varchar(500)                                      null comment 'id路径，逗号隔开'
)
    comment 'test';

select id from test where path like ‘%节点id%'