使用PIG读取XML [英] Reading XML using PIG

问题描述

我正在尝试使用PIG从xml文件读取数据，但是输出不完整.

I am trying to read the data from the xml file using PIG but I am getting incomplete output.

输入文件-

<document>   
<url>htp://www.abc.com/</url>
<category>Sports</category>
<usercount>120</usercount>
<reviews>    
<review>good site</review>
<review>This is Avg site</review>
<review>Bad site</review>
</reviews>
</document>

我正在使用的代码是:

register 'Desktop/piggybank-0.11.0.jar';
A = load 'input3' using org.apache.pig.piggybank.storage.XMLLoader('document') as (data:chararray);


 B = foreach A GENERATE FLATTEN(REGEX_EXTRACT_ALL(data,'(?s)<document>.*?<url>([^>]*?)</url>.*?<category>([^>]*?)</category>.*?<usercount>([^>]*?)</usercount>.*?<reviews>.*?<review>\\s*([^>]*?)\\s*</review>.*?</reviews>.*?</document>')) as (url:chararray,catergory:chararray,usercount:int,review:chararray);

我得到的输出是:

(htp://www.abc.com/,Sports,120,good site)

输出不完整.有人可以帮我解决我所缺少的吗?

which is incomplete output.Can someone please help on what I am missing?

推荐答案

呵呵！终于使用cross使它工作了.我正在使用XPath，如果需要，您可以使用正则表达式.我发现，XPath方式比正则表达式更简单，更干净.我想，您也可以看到它.不要忘记用XML替换testXML.xml.

huh!! Finally got it working using cross. I'm using XPath, you can use regex if you want. I find, XPath way to be easier and cleaner than regex. I guess, you can see it too. Don't forget to replace the testXML.xml with your XML.

XPath方式:

DEFINE XPath org.apache.pig.piggybank.evaluation.xml.XPath();
A = LOAD 'testXML.xml' using org.apache.pig.piggybank.storage.XMLLoader('document') as (x:chararray);
B = FOREACH A GENERATE XPath(x, 'document/url'), XPath(x, 'document/category'), XPath(x, 'document/usercount');
C = LOAD 'testXML.xml' using org.apache.pig.piggybank.storage.XMLLoader('review') as (review:chararray);
D = FOREACH C GENERATE XPath(review,'review');
E = cross B,D;
dump E;

正则表达式方式:

A = LOAD 'testXML.xml' using org.apache.pig.piggybank.storage.XMLLoader('document') as (x:chararray);
B = FOREACH A GENERATE FLATTEN(REGEX_EXTRACT_ALL(x,'(?s)<document>.*?<url>([^>]*?)</url>.*?<category>([^>]*?)</category>.*?<usercount>([^>]*?)</usercount>.*?</document>')) as (url:chararray,catergory:chararray,usercount:int);
C = LOAD 'testXML.xml' using org.apache.pig.piggybank.storage.XMLLoader('review') as (review:chararray);
D = FOREACH C GENERATE FLATTEN(REGEX_EXTRACT_ALL(review,'<review>([^>]*?)</review>'));
E = cross B,D;
dump E;

输出:

(htp://www.abc.com/,Sports,120,Bad site)
(htp://www.abc.com/,Sports,120,This is Avg site)
(htp://www.abc.com/,Sports,120,good site)

这不是您所期望的吗? ;)

Isn't that you were expecting? ;)

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