我的表如下table moneyquantity number(10),cdate number(10)
实际上就是存入一个数量和一个时间,理论上一个工作日有一条数据,前台要提供查询某一天数量,因为节假日及周末没有记录,如何查出这个数量呢,从概念上应该说是如果当天没有,就往前查看最近一条有数量的数.sql如何写最简洁.
实际上就是存入一个数量和一个时间,理论上一个工作日有一条数据,前台要提供查询某一天数量,因为节假日及周末没有记录,如何查出这个数量呢,从概念上应该说是如果当天没有,就往前查看最近一条有数量的数.sql如何写最简洁.
from (select quantity
from money
where sdate <= variable_date
order by sdate desc)
where rownum = 1
仅供参考
SELECT quantity FROM (SELECT quantity FROM tb WHERE cdate <= '20091214' ORDER BY cdate DESC) WHERE rownum = 1;
FROM (SELECT qty
FROM money
WHERE cdate <= DATE '2009-10-2'
AND qty != 0
ORDER BY cdate DESC)
WHERE rownum = 1
select quantity,cdate from money where cdate <to_date('2009-12-13','yyyy-mm-dd') order by cdate desc
) where rownum = 1;