hive把字符串转换为时间,Apache Hive：如何将字符串转换为时间戳？

I'm trying to convert the string in REC_TIME column to a timestamp format in hive.

Ex: Sun Jul 31 09:28:20 UTC 2016 => 2016-07-31 09:28:20

SELECT xxx, UNIX_TIMESTAMP(REC_TIME, "E M dd HH:mm:ss z yyyy") FROM wlogs LIMIT 10;

When I execute the above SQL it returns a NULL value.

解决方案

Try this :

select from_unixtime(unix_timestamp("Sun Jul 31 09:28:20 UTC 2016","EEE MMM dd HH:mm:ss zzz yyyy"));

This works fine if your hive cluster has UTC timezone. Say suppose your server is in CST then you need to do as below to get to UTC;

select to_utc_timestamp(from_unixtime(unix_timestamp("Sun Jul 31 09:28:20 UTC 2016","EEE MMM dd HH:mm:ss zzz yyyy")),'CST');

Hope this helps.

EDIT

Hive date functions use the JAVA simple date formater for the patterns . Refer this for the patterns.