Pig脚本连接到一个表中的两列，另一个表中有一列

Question

empdoc = load 'file_name' using PigStorage('\t') as (emp_id : chararray, emp_code : chararray, employee_internal_id : int);

masterdoc = load 'file_name' using PigStorage('\t')as (emp_internal_id : int, emp_id : chararray, mother_id : int, father_id : int, section_code : chararray);

childone = JOIN empdoc by (employee_internal_id), masterdoc by (mother_id) OR masterdoc by(father_id);

genone = FOREACH childone GENERATE employee_internal_id, emp_internal_id,emp_id, ;

基本上我正在尝试运行OR（如在SQL查询中）employee_internal_id = mother_id或father_id。

Answer 1

试试这个

empdoc = load 'file_name' using PigStorage('\t') as (emp_id : chararray, emp_code : chararray, employee_internal_id : int);

masterdoc = load 'file_name' using PigStorage('\t')as (emp_internal_id : int, emp_id : chararray, mother_id : int, father_id : int, section_code : chararray);

firstjoin = JOIN empdoc by (employee_internal_id), masterdoc by (mother_id) ;

genone = FOREACH firstjoin GENERATE employee_internal_id, emp_internal_id,emp_id ;

secondjoin=JOIN genone by (employee_internal_id) LEFT OUTER , masterdoc by (father_id) ;

result = FOREACH secondjoin GENERATE employee_internal_id, emp_internal_id,emp_id ;