Hive Union ALL - java nullpointer异常 [英] Hive Union ALL - java nullpointer exception

问题描述

 插入表all_data 
 select a，b from t1 
 union all 
从t2` 
中选择a，b  

上述查询工作正常。
当我将查询更改为以下内容：

 插入表all_data 
从t1中选择a，b 
 union all 
从t2中选择a，b 
 union all 
从t3中选择a，b 
  

我得到java空指针错误。所以我认为最后一个查询有问题。
然后我试试这个

 插入表all_data 
从t3 
中选择a，b  

它可行。
问题是联合所有查询都失败，但是它自己的查询起作用。
如何在Union All中使用任何指针？

解决方案

试试这个。

 插入表all_data 
 select * from（
从t1中选择a，b 
 union全部
选择a，b从t2 
 union all 
选择a，b从t3 
）u 
  

I have a Hive query which is something like this

insert into table all_data
  select a,b from t1
  union all
  select a,b from t2`

The above query works fine. When I change my query to following:

insert into table all_data
  select a,b from t1
  union all
  select a,b from t2
  union all
  select a,b from t3

I get java Null-pointer errors. SO I assume that the last query has an issue. Then I try this

insert into table all_data
  select a,b from t3

And it works. The problem is Union All the query fails but on its own the query works. Any pointers on how to get it working in Union All?

解决方案

try this.

insert into table all_data
select * from (
select a,b from t1
union all
select a,b from t2
union all
select a,b from t3
) u

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