1.oracle中当前系统时间加减用法
select add_months(sysdate, 12) "NEW YEAR" from dual; /**系统时间+12个月后的时间**/ select extract(month from sysdate) "This Month" from dual; /**获取系统时间所在月份**/ select (sysdate + 1) "NEW DATE" from dual; /**系统时间+1天后的时间**/
2.下面一日期处理函数为网上看到一并写在这里
create or replace function DATEADD(datepart varchar2, num number, indate date) return date is Result date; v_sql varchar2(1000); v_datepart varchar2(30); v_ms varchar2(13); begin v_datepart := lower(datepart); /* Datepart Abbreviations year yy, y quarter qq, q month mm, m day dd, d week wk, w hour hh, h minute mi, n second ss, s millisecond ms */ case when v_datepart in ('year', 'yy', 'y') then v_sql := 'select :1 + interval ''' || num || ''' year from dual'; when v_datepart in ('quarter', 'qq', 'q') then v_sql := 'select :1 + (interval ''3'' month) * ' || num || ' from dual'; when v_datepart in ('month', 'mm', 'm') then v_sql := 'select :1 + interval ''' || num || ''' month from dual'; when v_datepart in ('week', 'wk', 'w') then v_sql := 'select :1 + (interval ''7'' day) * ' || num || ' from dual'; when v_datepart in ('day', 'dd', 'd') then v_sql := 'select :1 + interval ''' || num || ''' day from dual'; when v_datepart in ('hour', 'hh') then v_sql := 'select :1 + interval ''' || num || ''' hour from dual'; when v_datepart in ('minute', 'mi', 'n') then v_sql := 'select :1 + interval ''' || num || ''' minute from dual'; when v_datepart in ('second', 'ss', 's') then v_sql := 'select :1 + interval ''' || num || ''' second from dual'; when v_datepart in ('millisecond', 'ms') then v_ms := to_char(num / 1000, 'fm999999990.000'); v_sql := 'select :1 + interval ''' || v_ms || ''' second(9,3) from dual'; else RAISE_APPLICATION_ERROR(-20001, '''' || datepart || ''' is not a recognized dateadd option.'); end case; execute immediate v_sql into Result using indate; return(Result); EXCEPTION WHEN OTHERS THEN RAISE; end DATEADD;