mysql/hive实现lead()不同偏移量数据

由于MySQL中不带有LEAD()函数功能,因此,参考着一篇已有的文档实现了不同偏移量的功能原文链接地址:mysql的lag和Lead函数
本文对比了hive和MySQL实现该功能的方式:

Hive实现方法
PS :空值处设置为NULL

select
 *
from
    (
        select
            orders as col_0,
            lead(orders, 1) over() as col_1,
            lead(orders 2) over() as col_2,
            lead(orders, 3) over() as col_3,
            lead(orders, 4) over() as col_4,
            lead(orders, 5) over() as col_5,
            lead(orders, 6) over() as col_6,
            lead(orders, 7) over() as col_7,
            lead(orders, 8) over() as col_8
        from
            t
    ) t

Mysql实现方法
PS :空值处设置为NULL

select
    t.dt,
    @lagfield:= @lagfield1 as col_1,
    @lagfield1:= @lagfield2 as col_2,
    @lagfield2:= @lagfield3 as col_3,
    @lagfield3:= @lagfield4 as col_4,
    @lagfield4:= @lagfield5 as col_5,
    @lagfield5:= @lagfield6 as col_6,
    @lagfield6:= @lagfield7 as col_7,
    @lagfield7:= @lagfield8 as col_8,
    @lagfield8:= @lagfield9 as col_9,
    @lagfield9:= orders as orders
from
   t,(
        select
            @lagfield:= null,
            @lagfield1:= null,
            @lagfield2:= null,
            @lagfield3:= null,
            @lagfield4:= null,
            @lagfield5:= null,
            @lagfield6:= null,
            @lagfield7:= null,
            @lagfield8:= null,
            @lagfield9:= null) init;

运行结果如下图:
mysql/hive实现lead()不同偏移量数据_第1张图片

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