常用日期查询汇总
1.求当年天数的sql语句SELECT ADD_MONTHS(TRUNC(SYSDATE, 'YYYY'), 12) - TRUNC(SYSDATE, 'YYYY') days FROM DUAL2.求当月天数的sql语句select to_number(add_months(trunc(sysdate, 'mm'), 1) - trunc(sysdate, 'mm')) from dual; 3，生成当年的所有月份 select TRUNC(SYSDATE, 'mm') + (rownum - 1)
from dual
connect by rownum <= (SELECT ADD_MONTHS(TRUNC(SYSDATE, 'YYYY'), 12) -
TRUNC(SYSDATE, 'YYYY') days
FROM DUAL);4, 获取每天的24个小时

select TRUNC(SYSDATE, 'dd') + (rownum - 1) / 24
from dual
connect by rownum <= 24;

select to_char(sysdate + (rownum - 1) / 24, 'hh24')
from dual
connect by rownum <= 24;

5, 获取每年的月份

Select add_months(trunc(sysdate, 'yyyy') ,Rownum - 1)
from dual
connect by rownum < 13;

6, 获取每月的天数

Select trunc(sysdate, 'mm') + Rownum - 1
from dual
connect by rownum < = (select to_number(add_months(trunc(sysdate, 'mm'), 1) -
trunc(sysdate, 'mm'))
from dual)

--本周

select trunc(sysdate, 'd') + 1 from dual;

select trunc(sysdate, 'd') + 7 from dual;

--本月

select trunc(sysdate, 'mm') from dual;

select last_day(trunc(sysdate)) from dual;

--本季

select trunc(sysdate, 'Q') from dual;

select add_months(trunc(sysdate, 'Q'), 3) - 1 from dual;

--本年

select trunc(sysdate, 'yyyy') from dual;

select add_months(trunc(sysdate, 'yyyy'), 12) - 1 from dual;

-- 获取上月的开始时间和结束时间

select to_char(to_date(to_char(add_months(sysdate, -1), 'yyyy-mm'),'yyyy-mm'),'yyyy-mm-dd hh24:mi:ss')

from dual;

select to_char(to_date(to_char(sysdate, 'yyyy-mm'), 'yyyy-mm'),'yyyy-mm-dd hh24:mi:ss')

from dual;

-- 获取前一天的开始时间和结束时间

select to_char(to_date(to_char(sysdate - 1, 'yyyy-mm-dd'), 'yyyy-mm-dd'),'yyyy-mm-dd hh24:mi:ss')

from dual;

select to_char(to_date(to_char(sysdate, 'yyyy-mm-dd'), 'yyyy-mm-dd'),'yyyy-mm-dd hh24:mi:ss')

from dual;

-- 获取上一个小时的开始时间和结束时间

select to_date(to_char(sysdate, 'yyyy-mm-dd') || (to_char(sysdate, 'hh24') - 1),'yyyy-mm-dd hh24')

from dual;

select to_date(to_char(sysdate, 'yyyy-mm-dd') || (to_char(sysdate, 'hh24')),'yyyy-mm-dd hh24')

from dual;