zoukankan      html  css  js  c++  java
  • SQLServer2005中的几个统计技巧

    先看下面的一个表格,我们从左边的两列信息来统计出右边的结果。

    在SQLServer中我们可以用over子句中来代替子查询实现来提高效率,over子句除了排名函数之外也可以和聚合函数配合。实现代码如下:


    use tempdb
    go
    if (object_id ('tb' ) is not null )
        drop table tb
    go
    create table tb (name varchar (10 ), val int )
    go
    insert into tb
    select 'aa' , 10
    union all select 'aa' , 20
    union all select 'aa' , 20
    union all select 'aa' , 30
    union all select 'bb' , 55
    union all select 'bb' , 45
    union all select 'bb' , 0

    select *
    , 排名 = rank ()over (partition by name order by val )
    , 占比 = cast (val * 1.0 / sum (val )over (partition by name ) as decimal (2 , 2 ))
    , 距最大 = val - max (val )over (partition by name )
    , 距最小 = val - min (val )over (partition by name )
    , 距平均 = val - avg (val )over (partition by name )
    from tb
  • 相关阅读:
    这几天都是在公司慢待
    电脑没有关机可能出现发博文dns异常(write)
    DOS/VBS
    SourceInsight
    CevaEclipse
    C/C++
    Matlab
    Matlab
    C语言
    Matlab
  • 原文地址:https://www.cnblogs.com/cl1024cl/p/6204812.html
Copyright © 2011-2022 走看看