i find that UDF can only process one argument like
public long evaluate(String ip) {
}
can i define a udf like  COALESCE(T v1, T v2, …) or  if(boolean testCondition, T valueTrue, T valueFalseOrNull)?
Chris Gong

Hi Chris,

Of course it is possible to write UDF with as many parameters as you want,
even with variable number of arguments. Have a look at the nice article
from Mark Grover [1] about writing UDFs. It also contains link to a
real-life example [2].

Best regards,
Jan Dolinar

[1] http://mark.thegrovers.ca/1/post/2012/06/how-to-write-a-hive-udf.html
[2]
https://github.com/markgrover/hive-translate/blob/master/GenericUDFTranslate.java

On Fri, Oct 19, 2012 at 5:36 AM, Chris Gong <[EMAIL PROTECTED]> wrote:

> **
> i find that UDF can only process one argument like
>    public long evaluate(String ip) {
>
>   }
>
> can i define a udf like  COALESCE(T v1, T v2, …) or  if(boolean
> testCondition, T valueTrue, T valueFalseOrNull)?
>
> ------------------------------
> Chris Gong
>

yes , it works , thank you very much  Jan.
Chris Gong

From: Jan Dolinár
Date: 2012-10-19 13:17
To: user; fellowtree
Subject: Re: can i define an udf which can process more than one argument?
Hi Chris,
Of course it is possible to write UDF with as many parameters as you want, even with variable number of arguments. Have a look at the nice article from Mark Grover [1] about writing UDFs. It also contains link to a real-life example [2].
Best regards,
Jan Dolinar
[1] http://mark.thegrovers.ca/1/post/2012/06/how-to-write-a-hive-udf.html
[2] https://github.com/markgrover/hive-translate/blob/master/GenericUDFTranslate.java

On Fri, Oct 19, 2012 at 5:36 AM, Chris Gong <[EMAIL PROTECTED]> wrote:

i find that UDF can only process one argument like
public long evaluate(String ip) {
}
can i define a udf like  COALESCE(T v1, T v2, …) or  if(boolean testCondition, T valueTrue, T valueFalseOrNull)?
Chris Gong

UDF can process multiple arguments. You just want to define the function
signature in that way.

For example,

evaluate(String s1, String s2, boolean t)
On Thu, Oct 18, 2012 at 11:36 PM, Chris Gong <[EMAIL PROTECTED]> wrote:

> **
> i find that UDF can only process one argument like
>    public long evaluate(String ip) {
>
>   }
>
> can i define a udf like  COALESCE(T v1, T v2, …) or  if(boolean
> testCondition, T valueTrue, T valueFalseOrNull)?
>
> ------------------------------
> Chris Gong
>

--
Chen Song