若要前行,就得离开你现在停留的地方。要有对自己纯粹而坚韧的标准,才可以跟着直觉和信念走去。自卑心最伤害自己,是最大的障碍。有时候阳光很好,有时候阳光很暗,这就是生活。
这一篇是对前面所有关于分析函数的文章的总结:
一、统计方面:
Sum() Over ([Partition by ] [Order by ])
Sum() Over ([Partition by ] [Order by ]
Rows Between Preceding And Following)
Sum() Over ([Partition by ] [Order by ]
Rows Between Preceding And Current Row)
Sum() Over ([Partition by ] [Order by ]
Range Between Interval '' 'Day' Preceding
And Interval '' 'Day' Following )
具体请参考《Oracle开发之分析函数简介Over用法》和《Oracle开发之窗口函数》
二、排列方面:
Rank() Over ([Partition by ] [Order by ] [Nulls First/Last])
Dense_rank() Over ([Patition by ] [Order by ] [Nulls First/Last])
Row_number() Over ([Partitionby ] [Order by ] [Nulls First/Last])
Ntile() Over ([Partition by ] [Order by ])
具体请参考《Oracle开发之分析函数(Rank, Dense_rank, row_number)》
三、最大值/最小值查找方面:
Min()/Max() Keep (Dense_rank First/Last [Partition by ] [Order by ])
具体请参考《Oracle开发之分析函数(Top/Bottom N、First/Last、NTile)》
四、首记录/末记录查找方面:
First_value / Last_value(Sum() Over ([Patition by ] [Order by ]
Rows Between Preceding And Following ))
具体请参考《Oracle开发之窗口函数》
五、相邻记录之间比较方面:
Lag(Sum(), 1) Over([Patition by ] [Order by ])
具体请参考《Oracle开发之报表函数》
以上就是Oracle分析函数总结的全部内容,希望能给大家一个参考,也希望大家多多支持。