How to create a key value map when there are duplicate keys? - mapreduce

Question

I am new to pig. I have the below output.
(001,Kumar,Jayasuriya,1123456754,Matara)
(001,Kumar,Sangakkara,112722892,Kandy)
(001,Rajiv,Reddy,9848022337,Hyderabad)
(002,siddarth,Battacharya,9848022338,Kolkata)
(003,Rajesh,Khanna,9848022339,Delhi)
(004,Preethi,Agarwal,9848022330,Pune)
(005,Trupthi,Mohanthy,9848022336,Bhuwaneshwar)
(006,Archana,Mishra,9848022335,Chennai)
(007,Kumar,Dharmasena,758922419,Colombo)
(008,Mahela,Jayawerdana,765557103,Colombo)
How can I create a map of the above so that the output will look something like,
001#{(Kumar,Jayasuriya,1123456754,Matara),(Kumar,Sangakkara,112722892,Kandy),(001,Rajiv,Reddy,9848022337,Hyderabad)}
002#{(siddarth,Battacharya,9848022338,Kolkata)}
I tried the ToMap function.
mapped_students = FOREACH students GENERATE TOMAP($0,$1..);
But I am unable dump the output from the above command as the process throws an error and stops there. Any help would be much appreciated.

Answer 1

I think you are trying to achieve is group records into tuples having same id.
according to TOMAP function it Converts key/value expression pairs into a map, hence you wont be able to group your rest records, and will result in something like unable to open iterator for alias..
as per your desiring output here is the piece of code.
A = LOAD 'path_to_data/data.txt' USING PigStorage(',') AS (id:chararray,first:chararray,last:chararray,phone:chararray,city:chararray);
If you do not want to give schema then:
A = LOAD 'path_to_data/data.txt' USING PigStorage(',');
B = GROUP A BY $0; (this relation will group all your records based on your first column)
DESCRIBE B; (this will show your described schema)
DUMP B;
Hope this helps..