XML Schema to Hive Schema

Question

I am trying to load a xml file into hive table. I am using xml serde here. I am able to load simple flat xml files. But when there are nested elements in the xml, I am using hive complex data types to store them (for e.g., array<struct>). Below is the sample xml that I am trying to load. My goal is to load all elements, attributes and content into hive table.

<description action="up">
    <name action="aorup" ln="te">
    this is name1
    </name>
    <name action="aorup" ln="tm">
    this is name2
    </name>
    <name action="aorup" ln="hi">
    this is name2
    </name>
</description>

Hive output that I am trying to get is...

{action:"up", name:[{action:"aorup", ln:"te", content:"this is name1"}, {action:"aorup", ln:"tm", content:"this is name2"}, {action:"aorup", ln:"hi", content:"this is name3"}]}

I wanted to load this entire xml into a single hive column. I tried the following:

CREATE TABLE description(
description STRUCT<
Action:STRING, 
name:ARRAY<STRUCT<
    Action:STRING, ln:STRING, content:STRING
    >>
>)
ROW FORMAT SERDE 'com.ibm.spss.hive.serde2.xml.XmlSerDe'
WITH SERDEPROPERTIES (
"xml.processor.class"="com.ximpleware.hive.serde2.xml.vtd.XmlProcessor",
"column.xpath.description"="/description")
STORED AS INPUTFORMAT 'com.ibm.spss.hive.serde2.xml.XmlInputFormat'
OUTPUTFORMAT 'org.apache.hadoop.hive.ql.io.IgnoreKeyTextOutputFormat'
TBLPROPERTIES ("xmlinput.start"="<description ","xmlinput.end"= "</description>");

But I am getting null value for Label field. Can someone help me?

Thanks

score 1 · Accepted Answer · answered Jun 09 '17 at 14:40

create external table description
(
    description struct<action:string,description:array<struct<action:string,ln:string,name:string>>>
)
row format serde 'com.ibm.spss.hive.serde2.xml.XmlSerDe'
with serdeproperties 
(
    "column.xpath.description" = "/description"
)
stored as 
inputformat     'com.ibm.spss.hive.serde2.xml.XmlInputFormat'
outputformat    'org.apache.hadoop.hive.ql.io.IgnoreKeyTextOutputFormat'
tblproperties   
(
    "xmlinput.start" = "<description "
   ,"xmlinput.end"   = "</description>"
)
;

select * from description
;

+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|                                                                                         description                                                                                         |
+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| {"action":"up","description":[{"action":"aorup","ln":"te","name":"this is name1"},{"action":"aorup","ln":"tm","name":"this is name2"},{"action":"aorup","ln":"hi","name":"this is name2"}]} |
+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

Thank you very much for the answer. Can you please explain the `create table` statement. It is confusing me. I tried your solution on another nested xml schema in this question [link](https://stackoverflow.com/questions/44494364/complex-xml-schema-to-hive-schema). but couldn't get the solution. . Can you please explain where I went wrong? — Sri Harsha Chennavajjala, Jun 12 '17 at 08:10

XML Schema to Hive Schema

1 Answers1