构造从2000年到2017年的年月日
--构造年
select to_char(add_months(to_date('1999', 'yyyy'), level * 12), 'yyyy') yearfrom dual
connect by level <= 18;--构造年月
select to_char(add_months(to_date('199912', 'yyyymm'), level), 'yyyymm') monthfrom dual
connect by level <= 18 * 12;--构造年月日
select to_char(to_date('19991231', 'yyyymmdd') + level, 'yyyymmdd') dayfrom dual
connect by level <= to_date('20171231', 'yyyymmdd') - to_date('19991231', 'yyyymmdd');