国产一级a片免费看高清,亚洲熟女中文字幕在线视频,黄三级高清在线播放,免费黄色视频在线看

帶時(shí)分秒 轉(zhuǎn)換成日期類型to_date('20120801 00:00:00','yyyymmdd HH24:Mi:SS')
六種日期函數(shù)：
1. add_months(日期，number) 指定日期推遲number個(gè)月
2. last_day(日期) 指定日期當(dāng)月的最后一天
3. new_time(日期，時(shí)區(qū)簡(jiǎn)寫) 調(diào)整時(shí)區(qū)
4. next_day(日期，number) number表示周幾，星期日是1，指定number的日期（一周內(nèi)或一周后）
5. months_between(日期1，日期2) 日期1和日期2之間有幾個(gè)月
6. sysdate 系統(tǒng)當(dāng)期那日期和時(shí)間

==================================================================
oracle plsql 對(duì)日期的處理函數(shù)和sql例子

102.取時(shí)間點(diǎn)的年份的寫法:
select to_char(sysdate,'yyyy') from dual;

103.取時(shí)間點(diǎn)的月份的寫法:
select to_char(sysdate,'mm') from dual;

104.取時(shí)間點(diǎn)的日的寫法:
select to_char(sysdate,'dd') from dual;

105.取時(shí)間點(diǎn)的時(shí)的寫法:
select to_char(sysdate,'hh24') from dual;

106.取時(shí)間點(diǎn)的分的寫法:
select to_char(sysdate,'mi') from dual;

107.取時(shí)間點(diǎn)的秒的寫法:
select to_char(sysdate,'ss') from dual;

108.取時(shí)間點(diǎn)的日期的寫法:
select trunc(sysdate) from dual;

109.取時(shí)間點(diǎn)的時(shí)間的寫法:
select to_char(sysdate,'hh24:mi:ss') from dual;

110.日期,時(shí)間形態(tài)變?yōu)樽址螒B(tài)
select to_char(sysdate) from dual;

111.將字符串轉(zhuǎn)換成日期或時(shí)間形態(tài):
select to_date('2003/08/01') from dual;

112.返回參數(shù)的星期幾的寫法:
select to_char(sysdate,'d') from dual;

113.返回參數(shù)一年中的第幾天的寫法:
select to_char(sysdate,'ddd') from dual;

114.返回午夜和參數(shù)中指定的時(shí)間值之間的秒數(shù)的寫法:
select to_char(sysdate,'sssss') from dual;

115.返回參數(shù)中一年的第幾周的寫法:
select to_char(sysdate,'ww') from dual;
==================================================================
練習(xí)時(shí)的代碼：
select to_number(to_char(last_day(add_months(to_date('20040406','yyyymmdd'),-1))+1,'yyyymmdd')) from dual;
------------------------------
20040401

select to_number(to_char(last_day(to_date('20040406','yyyymmdd')),'yyyymmdd')) from dual;
------------------------------
20040430

--select sysdate from dual; 當(dāng)前日期
--select last_day(sysdate) from dual; 月底日期
--select last_day(add_months(sysdate, -1)) from dual; 上月底日期
-- SELECT to_char(last_day(SYSDATE),'dd') days FROM dual; 當(dāng)前月的天數(shù)
--select last_day(add_months(sysdate,-1))+1 from dual; 當(dāng)前月第一天
--select to_number(to_char(sysdate,'yyyymmdd')) from dual;系統(tǒng)當(dāng)前日期轉(zhuǎn)換成如20070910格式：

==================================================================

create or replace procedure p_hkb_date_insert is
/*
過程功能描述：日期插入表中
*/
v_days number(10);
v_date date;
i number(10);
begin
  begin
    --取得當(dāng)月天數(shù)
    select to_number(to_char(last_day(sysdate), 'dd')) into v_days from dual;
  end;

  i := 1;
  begin
    select last_day(add_months(sysdate, -1)) into v_date from dual;
    while i <= v_days loop
      insert into hkb_date values(v_date + i, to_char(v_date + i, 'yyyymmdd'),to_number(to_char(v_date + i, 'yyyymmdd')));
      i := i + 1;
    end loop;
  end;
end p_hkb_date_insert;
==================================================================
create table hkb_date_construct as select * from hkb_date where 1=2; 繼承表字段
create table hkb_date_data as select * from hkb_date; 繼承表記錄