测试了很久，网上说的方法很多，其实都是错误的，正确的写法：

declare
    cursor rowAll is select * from tb_news where 1=1;
    row1 tb_news%rowtype;
    i int;
    begin
     
    i := 0;
    for row1 in rowAll
    loop        
        row1.id := fn_gen_getid('tb_news');
        row1.addtime := sysdate;
        row1.starttime := sysdate;
        row1.adduserid := -100;
        insert into tb_news values row1;
        commit;
    end loop;
end;

Oracle 复制任意表一行的SQL语句（测试Ok）