富贵资源网 Design By www.hznty.com
本文实例讲述了mysql滑动订单问题原理与解决方法。分享给大家供大家参考,具体如下:
先根据以下代码来创建表MonthlyOrders并导入一定的数据
CREATE TABLE MonthlyOrders( ordermonth DATE, ordernum INT UNSIGNED, PRIMARY KEY (ordermonth) );
INSERT INTO MonthlyOrders SELECT '2010-02-01',23; INSERT INTO MonthlyOrders SELECT '2010-03-01',26; INSERT INTO MonthlyOrders SELECT '2010-04-01',24; INSERT INTO MonthlyOrders SELECT '2010-05-01',27; INSERT INTO MonthlyOrders SELECT '2010-06-01',26; INSERT INTO MonthlyOrders SELECT '2010-07-01',32; INSERT INTO MonthlyOrders SELECT '2010-08-01',34; INSERT INTO MonthlyOrders SELECT '2010-09-01',30; INSERT INTO MonthlyOrders SELECT '2010-10-01',31; INSERT INTO MonthlyOrders SELECT '2010-11-01',32; INSERT INTO MonthlyOrders SELECT '2010-12-01',33; INSERT INTO MonthlyOrders SELECT '2011-01-01',31; INSERT INTO MonthlyOrders SELECT '2011-02-01',34; INSERT INTO MonthlyOrders SELECT '2011-03-01',34; INSERT INTO MonthlyOrders SELECT '2011-04-01',38; INSERT INTO MonthlyOrders SELECT '2011-05-01',39; INSERT INTO MonthlyOrders SELECT '2011-06-01',35; INSERT INTO MonthlyOrders SELECT '2011-07-01',49; INSERT INTO MonthlyOrders SELECT '2011-08-01',56; INSERT INTO MonthlyOrders SELECT '2011-09-01',55; INSERT INTO MonthlyOrders SELECT '2011-10-01',74; INSERT INTO MonthlyOrders SELECT '2011-11-01',75; INSERT INTO MonthlyOrders SELECT '2011-12-01',14;
滑动订单问题是指为每个月返回上一年度(季度或月度)的滑动订单数,即每个月份N,返回N-11到月份N的订单总数。这里,假设月份序列中不存在间断。
执行下面的SQL查询实现每个月返回上一年度的滑动订单总数
SELECT DATE_FORMAT(a.ordermonth, '%Y%m') AS frommonth, DATE_FORMAT(b.ordermonth, '%Y%m') AS tomonth, SUM(c.ordernum) AS orders FROM monthlyorders a INNER JOIN monthlyorders b ON DATE_ADD(a.ordermonth, INTERVAL 11 MONTH) = b.ordermonth INNER JOIN monthlyorders c ON c.ordermonth BETWEEN a.ordermonth AND b.ordermonth GROUP BY a.ordermonth,b.ordermonth;
运行结果如下图
该查询首先对MonthlyOrders表进行自连接。a表用做下边界(frommonth),b表用做上边界(tomonth)。连接的条件为:
DATE_ADD(a.ordermonth, INTERVAL 11 MONTH) = b.ordermonth
例如,a表中的2010年2月将匹配2011年1月。
完成自连接之后,需要对订单进行统计。这时需要再进行一次自连接,得到范围内每个月的订单数量。因此连接的条件为
c.ordermonth BETWEEN a.ordermonth AND b.ordermonth
基于上述方法,我们还可以统计每个季度订单的情况,以此作为和同比增长的比较依据。
SELECT DATE_FORMAT(a.ordermonth, '%Y%m') AS frommonth, DATE_FORMAT(b.ordermonth, '%Y%m') AS tomonth, SUM(c.ordernum) AS orders FROM monthlyorders a INNER JOIN monthlyorders b ON DATE_ADD(a.ordermonth, INTERVAL 2 MONTH) = b.ordermonth AND MONTH(a.ordermonth) % 3 = 1 INNER JOIN monthlyorders c ON c.ordermonth BETWEEN a.ordermonth AND b.ordermonth GROUP BY a.ordermonth,b.ordermonth;
运行结果如下图
更多关于MySQL相关内容感兴趣的读者可查看本站专题:《MySQL查询技巧大全》、《MySQL常用函数大汇总》、《MySQL日志操作技巧大全》、《MySQL事务操作技巧汇总》、《MySQL存储过程技巧大全》及《MySQL数据库锁相关技巧汇总》
希望本文所述对大家MySQL数据库计有所帮助。
富贵资源网 Design By www.hznty.com
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!
富贵资源网 Design By www.hznty.com
暂无评论...
RTX 5090要首发 性能要翻倍!三星展示GDDR7显存
三星在GTC上展示了专为下一代游戏GPU设计的GDDR7内存。
首次推出的GDDR7内存模块密度为16GB,每个模块容量为2GB。其速度预设为32 Gbps(PAM3),但也可以降至28 Gbps,以提高产量和初始阶段的整体性能和成本效益。
据三星表示,GDDR7内存的能效将提高20%,同时工作电压仅为1.1V,低于标准的1.2V。通过采用更新的封装材料和优化的电路设计,使得在高速运行时的发热量降低,GDDR7的热阻比GDDR6降低了70%。