摘要：SELECT T2.id, T2.SYSTEM_NAME FROM ( SELECT @r AS _id, (SELECT @r := parent_id FROM T_BUSI_SYSTEM WHERE id = _id) AS parent_id, @l := @l + 1 AS lvl FRO 阅读全文

摘要：public class Node { private int id; private int pid; private String name; private List<Node> sub = new ArrayList<>(); public Node(int id, int pid) { t 阅读全文