Date Format Conversion in Hive

Question

I'm very new to sql/hive. At first, I loaded a txt file into hive using:

drop table if exists Tran_data;
create table Tran_data(tran_time string, 
resort string, settled double)
ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t' LINES TERMINATED BY '\n';
Load data local inpath 'C:\Users\me\Documents\transaction_data.txt' into table Tran_Data;

The variable tran_time in the txt file is like this:10-APR-2014 15:01. After loading this Tran_data table, I tried to convert tran_time to a "standard" format so that I can join this table to another table using tran_time as the join key. The date format desired is 'yyyymmdd'. I searched online resources, and found this: unix_timestamp(substr(tran_time,1,11),'dd-MMM-yyyy')

So essentially, I'm doing this: unix_timestamp('10-APR-2014','dd-MMM-yyyy'). However, the output is "NULL".

So my question is: how to convert the date format to a "standard" format, and then further convert it to 'yyyymmdd' format?

Answer 1

from_unixtime(unix_timestamp('20150101' ,'yyyyMMdd'), 'yyyy-MM-dd') 

Answer 2

My current Hive Version: Hive 0.12.0-cdh5.1.5

I converted datetime in first column to date in second column using the below hive date functions. Hope this helps!

select inp_dt, from_unixtime(unix_timestamp(substr(inp_dt,0,11),'dd-MMM-yyyy')) as todateformat from table;

inp_dt todateformat
12-Mar-2015 07:24:55 2015-03-12 00:00:00