If any of the columns concatenated is NULL the result will be NULL. Use COALESCE function around each column. You also need to CAST the numeric fields to STRING to able to use COALESCE. You can use CONCAT_WS to put delimiters in between each column.
-Nicole From: Cdy Chen <dongyong.c...@gmail.com<mailto:dongyong.c...@gmail.com>> Reply-To: "user@hive.apache.org<mailto:user@hive.apache.org>" <user@hive.apache.org<mailto:user@hive.apache.org>> Date: Tuesday, July 17, 2012 6:26 AM To: "user@hive.apache.org<mailto:user@hive.apache.org>" <user@hive.apache.org<mailto:user@hive.apache.org>> Subject: How to CONCAT 18 columns Hi all, select CONCAT(product,test_date,test_type,context_id,fid,eval,capacity,no_of_platters,ast_rev,tester,line_id,floor_id,hstack_part_number,dcm_head,dcm_media,dcm_preamp,dcm_prime_rwrk,be_eval) from raw_data; It returns NULL. Why? And how to CONCAT so many columns? Looking forward your suggestion! Thank you!
