Oracle同行合并分组

select bookid,substr(max(sys_connect_by_path(author,'&&')),3) author

(select bookid,author,id,lag(id) over(partition by bookid order by id) pid

from (select bookid,author,rownum id from test))

select bookid,author,id,lag(id) over(order by id) pid

from (select bookid,author,rownum id from test);

select bookid,author,id,lag(id) over(partition by bookid order by id) pid

from (select bookid,author,rownum id from test);