Ah, easy enough! And if you have no groups, you just want the match, it seems
index of 0 works just fine.
select regexp_extract('junk:text:ua123','ua[0-9]+',0) from dual -- assumes you
have created a dummy hive table called dual
ua123
---
Mark E. Sunderlin
Solutions Architect |AOL Data Warehouse
P: 703-256-6935 | C: 540-327-6222
AIM: MESunderlin
22000 AOL Way | Dulles, VA | 20166
-----Original Message-----
From: Mark Grover [mailto:mgro...@oanda.com]
Sent: Thursday, October 27, 2011 2:10 PM
To: user@hive.apache.org
Subject: Re: Question on regexp_extract() , Index?
Mark,
It specifies the group that you want to be extract after the Regex has been
matched. Group numbers are 1-referenced. In the example you gave, the first
group corresponds to "the", the second group corresponds to "bar". A group in
Regex is specified by a pair of parenthesis.
You can also look at the source code to gain further understanding.
http://www.javasourcecode.org/html/open-source/hive/hive-0.7.1/org/apache/hadoop/hive/ql/udf/UDFRegExpExtract.java.html
Matcher is the API that is used to match the Regex. More on that at:
http://download.oracle.com/javase/1.4.2/docs/api/java/util/regex/Matcher.html
Mark
----- Original Message -----
From: "Mark Sunderlin" <mark.sunder...@teamaol.com>
To: "user@hive.apache.org" <user@hive.apache.org>
Sent: Thursday, October 27, 2011 1:57:08 PM
Subject: Question on regexp_extract() , Index?
I've been working with the hive regexp_extract(string subject, string pattern,
int index) command. In the hive language manual,
https://cwiki.apache.org/confluence/display/Hive/LanguageManual+UDF#LanguageManualUDF-StringFunctions,
the following description for this function is given:
Returns the string extracted using the pattern. e.g.
regexp_extract('foothebar', 'foo(.*?)(bar)', 2) returns 'bar.' Note that some
care is necessary in using predefined character classes: using '\s' as the
second argument will match the letter s; '
s' is necessary to match whitespace, etc. The 'index' parameter is the Java
regex Matcher group() method index. See docs/api/java/util/regex/Matcher.html
for more information on the 'index' or Java regex group() method.
I tried doing some basic web searches and cannot find what I seek,
understanding of what the Index value in the regexp() call does.
Where exactly is the information listed as, "See
docs/api/java/util/regex/Matcher.html?" Is it online somewhere?
---
Mark E. Sunderlin
Solutions Architect |AOL Data Warehouse
P: 703-256-6935 | C: 540-327-6222
AIM: MESunderlin
22000 AOL Way | Dulles, VA | 20166
