Question

我有一个包含以下数据的表：

dt  device  id  count
2018-10-05  computer    7541185957382   6
2018-10-20  computer    7541185957382   3
2018-10-14  computer    7553187775734   6
2018-10-17  computer    7553187775734   10
2018-10-21  computer    7553187775734   2
2018-10-22  computer    7549187067178   5
2018-10-20  computer    7553187757256   3
2018-10-11  computer    7549187067178   10

我想获取每个dt的最后一个id。因此，我使用了如下窗口函数first_value和last_value：

select id,last_value(dt) over (partition by id order by dt) last_dt
from table
order by id
;

但是我收到此错误：

FAILED: SemanticException Failed to breakup Windowing invocations into Groups. At least 1 group must only depend on input columns. Also check for circular dependencies.
Underlying error: Primitve type DATE not supported in Value Boundary expression

我无法诊断出问题，希望对您有所帮助。

Answer 1

如果在查询中添加行之间子句，则查询将正常工作。

hive> select id,last_value(dt) over (partition by id order by dt 
      rows between unbounded preceding and unbounded following) last_dt 
      from table order by id;

结果：

+----------------+-------------+--+
|       id       |   last_dt   |
+----------------+-------------+--+
| 7541185957382  | 2018-10-20  |
| 7541185957382  | 2018-10-20  |
| 7549187067178  | 2018-10-22  |
| 7549187067178  | 2018-10-22  |
| 7553187757256  | 2018-10-20  |
| 7553187775734  | 2018-10-21  |
| 7553187775734  | 2018-10-21  |
| 7553187775734  | 2018-10-21  |
+----------------+-------------+--+

有Jira关于原始类型支持的信息，并已在 Hive.2.1.0

中得到修复

更新：

对于不同的记录，您可以使用 ROW_NUMBER 窗口功能，并从结果集中仅过滤出first row。

hive> select id,last_dt from 
          (select id,last_value(dt) over (partition by id order by dt 
              rows between unbounded preceding and unbounded following) last_dt,
              ROW_NUMBER() over (partition by id order by dt)rn 
              from so )t 
           where t.rn=1;

结果：

+----------------+-------------+--+
|       id       |     dt      |
+----------------+-------------+--+
| 7541185957382  | 2018-10-20  |
| 7553187757256  | 2018-10-20  |
| 7553187775734  | 2018-10-21  |
| 7549187067178  | 2018-10-22  |
+----------------+-------------+--+

使用last_value窗口函数时，HIVE中的语义异常错误

1 个答案: