利用层次化查询解决某问题

create table test(id number, m number,lm number);--id唯一标识符，m为月份,lm为最大月份insert into test values(1,3,7);insert into test values(1,4,7);insert into test values(1,6,7);insert into test values(1,7,7);insert into test values(2,4,4);insert into test values(2,3,4);insert into test values(2,2,4);commit;select * from test;--求距离最大月份有记录的连续的月份个数--对于id=1则为2(6月和7月)--对于id=2则为3(4月，3月和2月)select id,max(level)from teststart with m = lmconnect by prior m = m + 1group by id;附上编写连续自然数记录：select rownum from dualconnect by level<=10;