配置单元加载特定列 [英] Hive load specific columns

问题描述

是否可以直接加载特定列，或者我应该加载所有数据并创建第二个表用于选择特定的列？

谢谢 解决方案

是的，你必须加载所有这样的数据：

  LOAD DATA [LOCAL] INPATH / Your / Path [OVERWRITE] INTO TABLE yourTable; 
  

LOCAL表示您的文件位于本地系统而不是HDFS中，OVERWRITE表示当前数据在表中将被删除。

所以你创建第二个只包含你需要的字段的表并执行这个查询：

  INSERT OVERWRITE TABLE yourNewTable 
 yourSelectStatement 
 FROM yourOldTable; 
  

I am interested in loading specific columns into a table created in Hive.

Is it possible to load the specific columns directly or I should load all the data and create a second table to SELECT the specific columns?

Thanks

解决方案

Yes you have to load all the data like this :

LOAD DATA [LOCAL] INPATH /Your/Path [OVERWRITE] INTO TABLE yourTable;

LOCAL means that your file is on your local system and not in HDFS, OVERWRITE means that the current data in the table will be deleted.

So you create a second table with only the fields you need and you execute this query :

INSERT OVERWRITE TABLE yourNewTable 
yourSelectStatement 
FROM yourOldTable;

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