sql over开窗函数

1.使用over子句与rows_number()以及聚合函数进行使用,可以进行编号以及各种操作。而且利用over子句的分组效率比group by子句的效率更高

2.在订单表(order)中统计中,生成这么每一条记录都包含如下信息:“所有订单的总和”、“每一位客户的所有订单的总和”、”每一单的金额“

  关键点:使用了sum() over() 这个开窗函数 

如图:

 

代码如下:

 

select 

  customerID,

  SUM(totalPrice) over() as AllTotalPrice,

  SUM(totalPrice) over(partition by customerID) as cusTotalPrice,

  totalPrice

  from OP_Order

 

 3.在订单表(order)中统计中,生成这么每一条记录都包含如下信息:“所有订单的总和(AllTotalPrice)”、“每一位客户的所有订单的总(cusTotalPrice)”、”每一单的金额(totalPrice)“,”每一个客户订单的平均金额(avgCusprice)“,”所有客户的所有订单的平均金额(avgTotalPrice)“,"客户所购的总额在所有的订单中总额的比例(CusAllPercent)","每一订单的金额在每一位客户总额中所占的比例(cusToPercent)"。

 

 

 

 

 代码如下

 with tabs as

 (

  select 

   customerID,

   SUM(totalPrice) over() as AllTotalPrice,

   SUM(totalPrice) over(partition by customerID) as cusTotalPrice,

   AVG(totalPrice) over(partition by customerID) as avgCusprice,

   AVG(totalPrice) over() as avgTotalPrice,

   totalPrice

 from OP_Order

 )

 select 

  customerID,

   AllTotalPrice,

   cusTotalPrice,

   totalPrice,

   avgCusprice,

   avgTotalPrice,

   cusTotalPrice/AllTotalPrice as CusAllPercent,

   totalPrice/cusTotalPrice as cusToPercent 

 from tabs

 

4.在订单表(order)中统计中,生成这么每一条记录都包含如下信息:“所有订单的总和(AllTotalPrice)”、“每一位客户的所有订单 的总(cusTotalPrice)”、”每一单的金额(totalPrice)“,”每一个客户订单的平均金额(avgCusprice)“,”所有客 户的所有订单的平均金额(avgTotalPrice)“,"订单金额最小值(MinTotalPrice)","客户订单金额最小值(MinCusPrice)","订单金额最大值(MaxTotalPrice)","客户订单金额最大值(MaxCusPrice)","客户所购的总额在所有的订单中总额的比例(CusAllPercent)","每一订单的金 额在每一位客户总额中所占的比例(cusToPercent)"。

关键:利用over子句进行操作。

 如图:

 

 具体代码如下:

 1  with tabs as

 2  (

 3   select 

 4  customerID,

 5  SUM(totalPrice) over() as AllTotalPrice,

 6  SUM(totalPrice) over(partition by customerID) as cusTotalPrice,

 7  AVG(totalPrice) over(partition by customerID) as avgCusprice,

 8  AVG(totalPrice) over() as avgTotalPrice,

 9  MIN(totalPrice) over() as MinTotalPrice,

10  MIN(totalPrice) over(partition by customerID) as MinCusPrice,

11  MAX(totalPrice) over() as MaxTotalPrice,

12  MAX(totalPrice) over(partition by customerID) as MaxCusPrice,

13  totalPrice

14  from OP_Order

15  )

16  select 

17  customerID,

18  AllTotalPrice,

19  cusTotalPrice,

20  totalPrice,

21  avgCusprice,

22  avgTotalPrice,

23  MinTotalPrice,

24  MinCusPrice,

25  MaxTotalPrice,

26  MaxCusPrice,

27  cusTotalPrice/AllTotalPrice as CusAllPercent,

28  totalPrice/cusTotalPrice as cusToPercent 

29  from tabs

 

 总结:领用聚合函数再结合over子句,可以使表格向右扩张。并进行一些数据的统计。

 

参考: over子句

      :over子句的详解 

 

转载自:http://www.cnblogs.com/85538649/archive/2011/08/13/2137370.html

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