kskp kskp - 1 month ago 6
JSON Question

Pig: Create json file with actual key_name and values

I have a pig script using elephant bird json loader.

data_input = LOAD '$DATA_INPUT' USING com.twitter.elephantbird.pig.load.JsonLoader() AS (json:map []);

x = FOREACH data_input GENERATE json#'user__id_str', json#'user__created_at', json#'user__notifications', json#'user__follow_request_sent', json#'user__friends_count', json#'user__name', json#'user__time_zone', json#'user__profile_background_color', json#'user__is_translation_enabled', json#'user__profile_link_color', json#'user__utc_offset', json#'user__profile_sidebar_border_color', json#'user__has_extended_profile', json#'user__profile_background_tile', json#'user__is_translator', json#'user__profile_text_color', json#'user__location', json#'user__profile_banner_url', json#'user__profile_use_background_image', json#'user__default_profile_image', json#'user__description', json#'user__profile_background_image_url_https', json#'user__profile_sidebar_fill_color', json#'user__followers_count', json#'user__profile_image_url', json#'user__geo_enabled', json#'user__entities__description__urls', json#'user__screen_name', json#'user__favourites_count', json#'user__url', json#'user__statuses_count', json#'user__default_profile', json#'user__lang', json#'user__protected', json#'user__listed_count', json#'user__profile_image_url_https', json#'user__contributors_enabled', json#'user__following', json#'user__verified';

STORE x INTO '$DATA_OUTPUT' USING JsonStorage();


I have the output right but the field names are wrong.

My output has
val_n
instaed of the field names themselves:

{"val_0":"40510796","val_1":"Sat May 16 18:03:53 +0000 2009","val_2":"false"......}


I want something like:

{"user__id_str":"40510796","user__created_at":"Sat May 16 18:03:53 +0000 2009","user__notifications":"false"...........}


How can I get the column names as well?

Answer

Have you tried giving Alias in generate statement:

x = FOREACH data_input GENERATE json#'user__id_str' AS user__id_str, json#'user__created_at' AS user__created_at;