用 Pig-Latin 打印哈希表？

Question

例如，我有这个数据：

x, 23
y, 492
v, 2034
x, 45
z, 25
v, 29

我想转换成：

x, 23, 45
y, 492
v, 2034, 29
z, 25

这相当于打印的散列 table。

这是我当前的脚本：

logs = LOAD 'tmp' using MyLoader (Parameters) as 
       (x:bytearray, y:bytearray, z, x1, y1:bytearray, z1:long, x2:bytearray,  
       z2:bytearray, z3:bytearray, z4:float, dataMap:map[], 
       recs:bag{(record:bytearray)}, key:bytearray, colo:bytearray);

filtered_logs = foreach logs { 
    info = FILTER records BY record MATCHES 'FIRST_REGEX';
    info_records = FOREACH info GENERATE GET_FIELDS([=12=]) as 
                   rec:tuple(mClass:bytearray, rType:bytearray, 
                   rName:bytearray, rStatus:bytearray, rDuration:float, 
                   rData:bytearray, rDataMap:map[]);

    name = FOREACH info_records GENERATE rec.rName;

    matching_requests = FILTER records BY record MATCHES 'SECOND_REGEX'; 

    GENERATE FLATTEN(client_name) as client_name:chararray, 
    dataMap#'corr_id_', (SIZE(matching_requests) > 0 ? true : false) 
    as matched:boolean;
}

A = FILTER filtered_logs BY matched; 

key_corr_id = foreach A generate (chararray)  as key, (chararray)  as corr_id;

id_group = group key_corr_id by key; -- ERROR thrown when this line is included.

STORE id_group into '$output' using 
org.apache.pig.piggybank.storage.CSVExcelStorage(, 'YES_MULTILINE');

抛出的错误：

java.lang.ClassCastException: org.apache.pig.data.DataByteArrayString cannot be cast to java.lang.String

Answer 1

无需创建新关系和 join.Just 按键分组并转储关系。

key_corr_id = foreach A generate (chararray)  as key:chararray, (chararray)  as corr_id:chararray;
id_group = group key_corr_id by key;
dump id_group;

现在，如果您不希望元组表示键 x , {(23),(45)} 但希望项目像 x,23,45 那样分开，则添加另一个步骤以在 corr_id在这样的分组中

final = foreach id_group generate key,BagToString(A., ',');
dump final;

用 Pig-Latin 打印哈希表？

Printed HashTable in Pig-Latin?

apache-pig