摘要:
1.trunc(for dates)为指定元素而截去的日期值--返回当年第一天select trunc(sysdate,'yyyy') from dual;orselect trunc(sysdate,'yy') from dual; --返回当月第一天select trunc(sysdate,'mm') from dual;--返回当前星期第一天select trunc(sysdate,'d') from dual;--返回当前年月日select trunc(sysdate,'dd') from dual;ors 阅读全文