MySQL中的WITH ROLLUP
来源:互联网 发布:不醉不会 田馥甄 知乎 编辑:程序博客网 时间:2024/05/16 18:38
MySQL的扩展SQL中有一个非常有意思的应用WITH ROLLUP,在分组的统计数据的基础上再进行相同的统计(SUM,AVG,COUNT…),非常类似于Oracle中统计函数的功能,Oracle的统计函数更多更强大。
下面演示单个司机以及所有司机的总行驶里程数和平均行驶里程数:
mysql> select name,sum(miles) as 'miles/driver'
-> from driver_log group by name with rollup;
+-------+--------------+
| name | miles/driver |
+-------+--------------+
| Ben | 362 |
| Henry | 911 |
| Suzi | 893 |
| NULL | 2166 |
+-------+--------------+
4 rows in set (0.00 sec)
mysql> select name,avg(miles) as driver_avg
-> from driver_log group by name with rollup;
+-------+------------+
| name | driver_avg |
+-------+------------+
| Ben | 120.6667 |
| Henry | 182.2000 |
| Suzi | 446.5000 |
| NULL | 216.6000 |
+-------+------------+
4 rows in set (0.00 sec)
mysql> select name,sum(miles) as 'miles/driver',avg(miles) as driver_avg
-> from driver_log group by name with rollup;
+-------+--------------+------------+
| name | miles/driver | driver_avg |
+-------+--------------+------------+
| Ben | 362 | 120.6667 |
| Henry | 911 | 182.2000 |
| Suzi | 893 | 446.5000 |
| NULL | 2166 | 216.6000 |
+-------+--------------+------------+
4 rows in set (0.00 sec)
在多个分组下WITH ROLLUP同样有效:
mysql> select srcuser,dstuser,count(*) from mail group by srcuser,dstuser;
+---------+---------+----------+
| srcuser | dstuser | count(*) |
+---------+---------+----------+
| barb | barb | 1 |
| barb | tricia | 2 |
| gene | barb | 2 |
| gene | gene | 3 |
| gene | tricia | 1 |
| phil | barb | 1 |
| phil | phil | 2 |
| phil | tricia | 2 |
| tricia | gene | 1 |
| tricia | phil | 1 |
+---------+---------+----------+
10 rows in set (0.05 sec)
mysql> select srcuser,dstuser,count(*) from mail group by srcuser,dstuser with rollup;
+---------+---------+----------+
| srcuser | dstuser | count(*) |
+---------+---------+----------+
| barb | barb | 1 |
| barb | tricia | 2 |
| barb | NULL | 3 |
| gene | barb | 2 |
| gene | gene | 3 |
| gene | tricia | 1 |
| gene | NULL | 6 |
| phil | barb | 1 |
| phil | phil | 2 |
| phil | tricia | 2 |
| phil | NULL | 5 |
| tricia | gene | 1 |
| tricia | phil | 1 |
| tricia | NULL | 2 |
| NULL | NULL | 16 |
+---------+---------+----------+
15 rows in set (0.00 sec)
- MySQL中的WITH ROLLUP
- MySQL中的WITH ROLLUP
- MySQL中的WITH ROLLUP
- MySQL中的WITH ROLLUP
- mysql中的with rollup
- MySQL WITH ROLLUP
- MYSQL API之 WITH ROLLUP
- mysql group by with rollup
- MySQL中with rollup的用法
- mysql 之with rollup 的使用
- 使用mysql中的with rollup得到group by的汇总信息
- MYSQL group by 语句中的with rollup是用来干什么的?
- 使用mysql中的with rollup得到group by的汇总信息
- 使用mysql中的with rollup得到group by的汇总信息
- WITH ROLLUP在zend framework中的写法
- Mysql的with rollup功能(5.1以上版本)
- mysql group by 使用技巧及其with rollup使用
- Mysql 使用with rollup对聚合结果进行聚合
- 编译连接的过程
- 并查集水题 POJ2524
- android studio fetching android sdk 在mac 取消first run方法
- 通关的小游戏
- Zend studio 的两种插件之一 SVN插件
- MySQL中的WITH ROLLUP
- 二叉树的镜像--递归和迭代分别实现
- qCon大会小结
- Linux下tar.gz文件的安装
- Maximum Absurdity
- java Web的常见问题
- C语言简单解密
- 一个简单GOLANG路由
- Loader异步装载器