One way to debug is to put bash in action
say you have a data file in hdfs (/data/rockers/rockers.csv) that looks like
cust_num,cust_name,instrument1,paul,bass2,john,rhythm3,ringo,drums4,george,lead
to get the column=cust_num of data (in this case its column 1)
hdfs dfs -cat /data/rockers/rockers.csv | cut -d, -f 1 > /path/to/local/file.txt
If file is tab separated
cust_num cust_name instrument1 paul bass2 john rhythm3
ringo drums4 george lead
hdfs dfs -cat /data/rockers/rockers.csv | tr '\t' ',' | cut -d, -f 1 >
/path/to/local/file.txt
From: Nitin Pawar <nitinpawar...@gmail.com>
To: Raj Hadoop <hadoop...@yahoo.com>; user@hive.apache.org
Sent: Monday, October 20, 2014 12:11 PM
Subject: Re: select * from table and select column from table in hive
whats your table create ddl?is the data in csv like format?
On 21 Oct 2014 00:26, "Raj Hadoop" <hadoop...@yahoo.com> wrote:
I am able to see the data in the table for all the columns when I issue the
following -
SELECT * FROM t1 WHERE dt1='2013-11-20'
But I am unable to see the column data when i issue the following -
SELECT cust_num FROM t1 WHERE dt1='2013-11-20'
The above shows null values.
How should I debug this ?
