create table cat(

    id int unsigned not null primary key auto_increment,

    pid int unsigned not null default 0,

    path varchar(200) not null default '',

    name char(30) not null default ''

)engine=MyISAM default charset=utf8;

insert into cat (pid,path,name) values(0,0,'soft'),(0,0,'net'),(1,'0,1','java'),(1,'0,1','php'),(3,'0,1,3','j2se'),(3,'0,1,3','j2ee'),(4,'0,1,4','smarty'),(4,'0,1,4','thinkphp'),(8,'0,1,4,8','xmlyz'),(6,'0,1,3,6','jsp');

select id, concat(path, ',', id) as abspath from cat order by abspath,id;