hadoop - pig 过滤器不工作

Question

我有以下 pig 脚本，

meta_file = LOAD 'meta_file' USING PigStorage(',');

DUMP meta_file;

meta = FOREACH meta_file GENERATE (chararray)$0 AS is_vta:chararray, (chararray)$1 AS id:long;

DUMP meta;

new_d = FILTER meta BY (is_vta == 't');
DUMP new_d;

元文件的内容:

"t","7181397"
"t","6331589"
"f","7266217"
"t","6051440"
"t","6901437"
"t","6805292"
"f","7144764"
"t","6820265"
"f","7515321"
"t","4777938"

meta_file 的 DUMP 完全没问题，与文件的内容相同，meta 的内容也是如此，但是 new_d 是空的。我可以看到 meta 中有 is_vta，其值为 t，但 new_d 仍然是空的。为什么 meta 没有被正确过滤？我在这里做错了什么？我是 Pig Latin 的新手，无法弄清楚这里可能存在的问题。

感谢您的帮助。

Answer 1

简单的方法:

new_d = FILTER meta BY is_vta MATCHES '.*t.*';

另一种解决方案:

remquotes = FOREACH meta GENERATE REPLACE($0, '\\"', '') AS is_vta:chararray, id;

new_d = FILTER remquotes BY is_vta == 't';