1.OLAP函数 ROW_NUMBER 提供行号
select row_number() over (order by 字段) as row_no from tabname
查询表的第N行到第M行的数据
select a.* from ( select row_number() over (order by 字段) as row_no,a.* from tabname a )T where t.row_no between 1 and 100
2.OLAP查询
累计一个星期内每天的销售数字
sum(sum(?)) over (partition by week order by date rows unbounded preceding) as
OLAP分割： partition by
row n preceding 窗口帧
n=2表示当前行加上前两行，计算的是第三行的数据
3.OLAP RANK函数
RANK() OVER (partition by dept order by dollors desc nulls last )AS RANK
RANK 1,2,2,4
DENSE_RANK 1,2,2,3
ROW_NUMBER 1,2,3,4
按部门分割，降序，若有空值将被排到后面
相关资源：DB2中OLAP函数
