Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
Pig, mail # user - CONCAT(null, "something") == NULL ?


Copy link to this message
-
Re: CONCAT(null, "something") == NULL ?
Alan Gates 2012-11-02, 22:33
To give some context, the null semantics in Pig follow SQL's.  In SQL, null is viral, so any operation with null results in null.  The idea is that null means unknown, not empty.  So concat('x', unknown) = unknown.

Alan.

On Nov 2, 2012, at 3:09 PM, Yang wrote:

> looks a more intuitive result should be "something" , right?
>
> but on my system it gave null