数据库表有3列,Id,Name,ParentId,已从数据库读出数据,如何递归成一棵树...答:数据库是什么数据库?我先假设你是 Oracle 吧。CREATE TABLE test_tree (test_id INT NOT NULL,pid INT,test_val VARCHAR(10),PRIMARY KEY (test_id));INSERT INTO test_tree VALUES(1, NULL, '.NET');INSERT INTO test_tree VALUES(2, 1, 'C#');INSERT INTO test_tree...