select * from emp order by to_char(hiredate,'yyyy-mm-dd hh24:mi:ss') desc; 排序一下,就行了。
select * from emp order by to_char(hiredate,'yyyy-mm-dd hh24:mi:ss') desc; 排序
用>=或者<= 加排序后,取rownum=1的
--假设表名为tb,时间字段为dt_time,则: select x.* from(select t.*,row_number()over(order by dt_time desc) rn from tb t where t.dt_time <= sysdate )x where x.rn = 1;
select x.* from (select e.*,row_number()over(order by hiredate desc) sn from emp e where e.hiredate<=sysdate) x where x.sn=1;
select * from (select * from tb order by 时间字段 desc) where rownum<=1
select * from (select * from tb order by sysdate-时间字段) where rownum<=1
排序一下,就行了。
排序
--假设表名为tb,时间字段为dt_time,则:
select x.*
from(select t.*,row_number()over(order by dt_time desc) rn
from tb t
where t.dt_time <= sysdate
)x
where x.rn = 1;
(select e.*,row_number()over(order by hiredate desc) sn
from emp e
where e.hiredate<=sysdate) x
where x.sn=1;
from (select * from tb order by 时间字段 desc)
where rownum<=1
select *
from (select * from tb order by sysdate-时间字段)
where rownum<=1