question Re: Derived column created as _c0 in Hive . Cant access _c0 in Archives of Support Questions (Read Only)

Derived column created as _c0 in Hive . Cant access _c0

amit_dass — Tue, 10 May 2016 15:50:17 GMT

1) I had extracted data from xml .

2) I am getting the data correctly as below

hive> select * from xml_table;

1 Satish Kumar Technical Lead

2 Ramya Testing

hive> describe xml_table;

_c0 int

_c1 string

_c2 string

issue : .. When I try to access only _c0 column , I am getting error as below

hive> select _c0,_c1 from xml_table;

FAILED: ParseException line 1:10 missing \' at ',' near '<EOF>' line

1:15 missing \' at 'from' near '<EOF>'

Re: Derived column created as _c0 in Hive . Cant access _c0

bwalter1 — Tue, 10 May 2016 15:58:36 GMT

Try

select `_c0` from xml_table

Re: Derived column created as _c0 in Hive . Cant access _c0

amit_dass — Tue, 10 May 2016 16:05:26 GMT

I tried @Bernhard Walter : But I am not getting values

hive> select '_c0' from xml_table;

Total jobs = 1 Launching Job 1 out of 1 Number of reduce tasks is set to 0 since there's no reduce operator Starting Job = job_1461307169071_0063, Tracking URL = http://CDCUDHDOOPAPP02:8088/proxy/application_1461307169071_0063/ Kill Command = /chroot/hadoop/inst/hadoop/hadoop-2.4.0/bin/hadoop job -kill job_1461307169071_0063 Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 0 2016-05-10 14:33:40,593 Stage-1 map = 0%, reduce = 0% 2016-05-10 14:33:45,811 Stage-1 map = 100%, reduce = 0%, Cumulative CPU 0.96 sec MapReduce Total cumulative CPU time: 960 msec Ended Job = job_1461307169071_0063 MapReduce Jobs Launched: Job 0: Map: 1 Cumulative CPU: 0.96 sec HDFS Read: 265 HDFS Write: 8 SUCCESS Total MapReduce CPU Time Spent: 960 msec

_c0

Time taken: 17.912 seconds, Fetched: 2 row(s)

Re: Derived column created as _c0 in Hive . Cant access _c0

bwalter1 — Tue, 10 May 2016 16:07:35 GMT

Use backticks ` and not '

Re: Derived column created as _c0 in Hive . Cant access _c0

bwalter1 — Tue, 10 May 2016 16:09:53 GMT

For quoting identifiers see, e.g. https://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.3.0/bk_dataintegration/content/hive-013-feature-quoted-identifiers.html

Re: Derived column created as _c0 in Hive . Cant access _c0

amit_dass — Tue, 10 May 2016 16:30:20 GMT

Great !! @Bernhard Walter . Thanks for your help.