arrays - Hive Array>插入显示null

Question

我创建了一个包含结构数组的临时表

create table temp (regionkey smallint, name string, comment string, nations array<struct<n_nationkey:smallint,n_name:string,n_comment:string>>) 
ROW FORMAT DELIMITED 
FIELDS TERMINATED BY '|' 
COLLECTION ITEMS TERMINATED BY ',';

然后我将数据加载到表中

LOAD DATA LOCAL INPATH '/Data Sets/region.csv' INTO TABLE temp;

什么时候需要的输出

select * from temp;

是

4   EUROPE  Low sale Business Region [{"n_nationkey":22,"n_name":"Ryan","n_comment":"Reference the site"}]

但实际输出是

4   EUROPE  Low sale Business Region    [{"n_nationkey":22,"n_name":null,"n_comment":null},{"n_nationkey":null,"n_name":null,"n_comment":null},{"n_nationkey":null,"n_name":null,"n_comment":null}]

数据文件

4|EUROPE|Low sale Business Region for Training4Exam.com|7,Bulgaria,Reference 
4|EUROPE|Low sale Business Region for HadoopExam.com|19,Belgium,Reference site 
4|EUROPE|Low sale Business Region for Training4Exam.com|22,Ryan,Reference site

这是我第一次参加数组和结构考试，对此我一无所知。非常感谢任何帮助。谢谢

Answer 1

以 ',' 结尾的映射键

---

create external table temp 
(
    regionkey   smallint
   ,name        string
   ,comment     string
   ,nations     array<struct<n_nationkey:smallint,n_name:string,n_comment:string>>
) 
row format delimited 
fields terminated by '|' 
map keys terminated by ','
;

---

select * from temp
;

---

+-----------+--------+------------------------------------------------+-----------------------------------------------------------------------+
| regionkey |  name  |                    comment                     |                                nations                                |
+-----------+--------+------------------------------------------------+-----------------------------------------------------------------------+
|         4 | EUROPE | Low sale Business Region for Training4Exam.com | [{"n_nationkey":7,"n_name":"Bulgaria","n_comment":"Reference "}]      |
|         4 | EUROPE | Low sale Business Region for HadoopExam.com    | [{"n_nationkey":19,"n_name":"Belgium","n_comment":"Reference site "}] |
|         4 | EUROPE | Low sale Business Region for Training4Exam.com | [{"n_nationkey":22,"n_name":"Ryan","n_comment":"Reference site"}]     |
+-----------+--------+------------------------------------------------+-----------------------------------------------------------------------+

仅供引用

To be backward-compatible, initialize the first 3 separator to be the given values from the table properties.
The default number of separators is 8;
if only hive.serialization.extend.nesting.levels is set, the number of separators is extended to 24;
if hive.serialization.extend.additional.nesting.levels is set, the number of separators is extended to 154.
@param tableProperties table properties to extract the user provided separators

https://github.com/apache/hive/blob/master/serde/src/java/org/apache/hadoop/hive/serde2/lazy/LazySerDeParameters.java