教你快速掌握一些经常用到的"SQL"语句

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

select trunc(add_months(sysdate,1),"mm") from dual;

select last_day(sysdate) from dual;
select last_day(trunc(sysdate)) from dual;
select trunc(last_day(sysdate)) from dual;
select trunc(add_months(sysdate,1),"mm") - 1 from dual;

select trunc(sysdate,"yyyy")+ rn -1 date0
from
(select rownum rn from all_objects
where rownum<366);

SELECT TO_CHAR(SYSDATE,"DDD") FROM DUAL;

select add_months(sysdate,24) from dual;

select decode(to_char(last_day(trunc(sysdate,"y")+31),"dd"),"29","闰年","平年") from dual;

select decode(to_char(last_day(trunc(add_months(sysdate,24),"y")+31),
"dd"),"29","闰年","平年") from dual;

select ceil(to_number(to_char(sysdate,"mm"))/3) from dual;

select to_char(sysdate, "Q") from dual;