create_time时间格式 SELECT DATE_FORMAT(create_time,'%Y%u') weeks,COUNT(id) COUNT FROM role GROUP BY weeks; SELECT DATE_FORMAT(create_time,'%Y%m%d') days,COUNT(id) COUNT FROM role GROUP BY days; SELECT DATE_FORMAT(create_time,'%Y%m') months,COUNT(id) COUN
//1.将所有区间按左端点从小到大排序 //2.从前往后处理每个区间,判断能否将其放到某个现有的组中 //判断某一组的最后一个区间的右端点是否小于该区间的左端点 //如果大于或等于,就开新组,如果小于,就放到组里去,并更新最后一个区间的右端点 #include <iostream> #include <algorithm> #include <queue> using namespace std; ; int n; struct Range { int l, r; bo
To the moonTime Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://acm.hust.edu.cn/vjudge/contest/view.action?cid=88748#problem/I Description To The Moon is a independent game released in November 2011, it is a role-playing adventure game powered by RPG
做个笔记 SQLyog客户端访问MySQL服务器 统计数据:次数总数, 次数成功率,对象(obj)总数,对象(obj)成功率 要求:按时间排序和分组 sql语句如下: SELECT a.date AS `日期`, a.total AS `总次数`, a.objs AS `总对象数`, , ) AS `失败次数比率`, , ) AS `对象失败率` FROM (SELECT ) AS `total`, COUNT(DISTINCT(`obj_id`)) AS `objs`, , NULL)) AS
方法:mysql取分组后最新的一条记录,下面两种方法.一种是先筛选 出最大和最新的时间,在连表查询.一种是先排序,然后在次分组查询(默认第一条),就是最新的一条数据了 #select * from t_assistant_article as a, (select max(base_id) as base_id, max(create_time) as create_time from t_assistant_article as b group by base_id ) as b where
时间格式化 做博客后台时,需要经常对数据库里面的时间格式(2017-02-17 02:10:44.308638)进行处理,格式化成自己想要的时间(列如年月日),下面就来记录下如何对时间进行处理 1.时间进行格式化分组 class Article(models.Model): nid = models.BigAutoField(primary_key=True) title = models.CharField(verbose_name='文章标题', max_length=128) summar
开发中经常会遇到,分组查询最新数据的问题,比如下面这张表(查询每个地址最新的一条记录): sql如下: -- ---------------------------- -- Table structure for test -- ---------------------------- DROP TABLE IF EXISTS `test`; CREATE TABLE `test` ( `id` ) NOT NULL AUTO_INCREMENT, `name` ) CHARACTER SET
