教你快速掌握Sybase IQ常用分析型函数

教你快速掌握Sybase IQ常用分析型函数
  很多人都知道，Sybase IQ是高性能的数据仓库引擎，在SQL编程方面，它也引入了许多新的特性，分析型函数就是其中之一。常用的分析型函数如下：Grouping( ), Variance( )，StdDev( ), Rank( ), Dense_Rank( ),Percentile_Disc( )， Percentile_Count( ), Ntile( )等。

在实际的工作和学习中，使用以上的分析型函数，可以为用户的前端编程或者后台SQL编程带来极大的方便。

以上函数的简单示例如下：



select top 10 taxpayercode ,sum(mny_seze) as mny_seze_sukm, sum(mny_srze) as mny_srze_sum, DENSE_RANK() over( order by mny_srze_sum desc) as rank_all

from tqa_f_nsrqusb where id_mth=200702

group by taxpayercode

order by rank_all



select taxpayercode ,sum(mny_seze) as mny_seze_sukm,sum(mny_srze) as mny_srze_sum

from tqa_f_nsrqusb where id_mth=200702

group by taxpayercode order by mny_srze_sum desc



select top 10 taxpayercode ,sum(seze) as seze , NTILE(2) over ( order by seze desc) as ntile

from whtaxpayertaxbook where yr_sb=2005 and mth_sb=1

group by taxpayercode

order by seze


select top 10 taxpayercode, sum(seze) as seze, percent_rank() over (order by seze desc) as per_rank

from whtaxpayertaxbook where yr_sb=2005 and mth_sb=1

group by taxpayercode

order by seze


select top 10 taxpayercode, sum(seze) as seze, rank() over (order by seze desc) as per_rank

from whtaxpayertaxbook where yr_sb=2005 and mth_sb=1

group by taxpayercode

order by seze

注：在Oracle数据库9i以上的版本中也有类似的分析型函数，实现的功能也与此示例相似。