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基于一列的配置单元自连接

hiveql sap hive

0

Shekhar · 技术社区 · 8 年前

我在Hive中有一个表,其中的数据来自SAP系统。此表包含以下列和数据:

+======================================================================+
|document_number | year | cost_centre | vendor_account_number | amount | 
+----------------------------------------------------------------------+
|       1        | 2016 |     XZ10    |                       |  123.5 |
+----------------------------------------------------------------------+
|       1        | 2016 |     XZ10    |      1234567890       |  25.96 |
+----------------------------------------------------------------------+
|       1        | 2016 |     XZ10    |                       |  586   |
+----------------------------------------------------------------------+

vendor_account_number 列只存在于一行中,我想将其带到所有其他行中。

+======================================================================+
|document_number | year | cost_centre | vendor_account_number | amount | 
+----------------------------------------------------------------------+
|       1        | 2016 |     XZ10    |      1234567890       |  123.5 |
+----------------------------------------------------------------------+
|       1        | 2016 |     XZ10    |      1234567890       |  25.96 |
+----------------------------------------------------------------------+
|       1        | 2016 |     XZ10    |      1234567890       |  586   |
+----------------------------------------------------------------------+

为了实现这一点,我在Hive中编写了以下CTE

with non_blank_account_no as(
  select document_number, vendor_account_number
  from my_table
  where vendor_account_number != ''
)

然后进行自左外连接,如下所示:

select 
    a.document_number, a.year, 
    a.cost_centre, a.amount,
    b.vendor_account_number
from my_table a
left outer join non_blank_account_no b on a.document_number = b.document_number
where a.document_number = ' '

但我得到了如下所示的重复输出

+======================================================================+
|document_number | year | cost_centre | vendor_account_number | amount | 
+----------------------------------------------------------------------+
|       1        | 2016 |     XZ10    |      1234567890       |  123.5 |
+----------------------------------------------------------------------+
|       1        | 2016 |     XZ10    |      1234567890       |  25.96 |
+----------------------------------------------------------------------+
|       1        | 2016 |     XZ10    |      1234567890       |  586   |
+----------------------------------------------------------------------+
|       1        | 2016 |     XZ10    |      1234567890       |  123.5 |
+----------------------------------------------------------------------+
|       1        | 2016 |     XZ10    |      1234567890       |  25.96 |
+----------------------------------------------------------------------+
|       1        | 2016 |     XZ10    |      1234567890       |  586   |
+----------------------------------------------------------------------+

谁能帮我理解我的蜂巢查询出了什么问题?

1 回复 | 直到 8 年前

1

David ×××× Markovitz 8 年前

在许多用例中,自连接可以被windows函数替换

select  document_number
       ,year
       ,cost_center

       ,max (case when vendor_account_number <> '' then vendor_account_number end) over 
        (
            partition by    document_number
        )                                       as vendor_account_number

       ,amount

from    my_table