小编典典

Pig:JSON加载程序的结果为空

json

我正在使用cdh5 quickstart vm,并且我有一个像这样的文件(此处不完整):

{"user_id": "kim95",
 "type": "Book",
 "title": "Modern Database Systems: The Object Model, Interoperability, and
Beyond.",
 "year": "1995",
 "publisher": "ACM Press and Addison-Wesley",
 "authors": {},
 "source": "DBLP"
}
{"user_id": "marshallo79",
 "type": "Book",
 "title": "Inequalities: Theory of Majorization and Its Application.",
 "year": "1979",
 "publisher": "Academic Press",
 "authors": {("Albert W. Marshall"), ("Ingram Olkin")},
 "source": "DBLP"
}

我使用了这个脚本:

books = load 'data/book-seded.json'
        using JsonLoader('t1:tuple(user_id:
chararray,type:chararray,title:chararray,year:chararray,publisher:chararray,source:chararray,authors:bag{T:tuple(author:chararray)})');

STORE books INTO 'book-no-seded.tsv';

该脚本有效,但是生成的文件为空,您有什么想法吗?


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2020-07-27

共1个答案

小编典典

最后,只有此模式有效:如果我添加或删除与该配置不同的空格,那么我将出现错误(我还为元组添加了“名称”,并在其为空时指定了“
null”,并更改了作者之间的顺序和来源,但即使没有这种配置,它仍然是错误的)

{"user_id": "kim95", "type": "Book","title": "Modern Database Systems: The Object Model, Interoperability, and Beyond.", "year": "1995", "publisher": "ACM Press and Addison-Wesley", "authors": [{"name":null"}], "source": "DBLP"}
{"user_id": "marshallo79", "type": "Book", "title": "Inequalities: Theory of Majorization and Its Application.", "year": "1979", "publisher": "Academic Press", "authors": [{"name":"Albert W. Marshall"},{"name":"Ingram Olkin"}], "source": "DBLP"}

工作脚本是这个:

books = load 'data/book-seded-workings-reduced.json'
        using JsonLoader('user_id:chararray,type:chararray,title:chararray,year:chararray,publisher:chararray,authors:{(name:chararray)},source:chararray');

STORE books INTO 'book-table.csv';  //whether .tsv or .csv
2020-07-27