程序師世界是廣大編程愛好者互助、分享、學習的平台,程序師世界有你更精彩!
首頁
編程語言
C語言|JAVA編程
Python編程
網頁編程
ASP編程|PHP編程
JSP編程
數據庫知識
MYSQL數據庫|SqlServer數據庫
Oracle數據庫|DB2數據庫
 程式師世界 >> 數據庫知識 >> MYSQL數據庫 >> MySQL綜合教程 >> MySQL中的WITHROLLUP

MySQL中的WITHROLLUP

編輯:MySQL綜合教程

MySQL中的WITHROLLUP


MySQL的擴展SQL中有一個非常有意思的應用WITH ROLLUP,在分組的統計數據的基礎上再進行相同的統計(SUM,AVG,COUNT…),非常類似於Oracle中統計函數的功能,Oracle的統計函數更多更強大。

下面演示單個司機以及所有司機的總行駛裡程數和平均行駛裡程數:

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)

在多個分組下WITH ROLLUP同樣有效:

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)

 

  1. 上一頁:
  2. 下一頁:
Copyright © 程式師世界 All Rights Reserved