I don’t know about Drill, but in Calcite you declare the function (SqlOperator) 
such that the getSyntax() method returns SqlSyntax.FUNCTION_ID. 
SqlCurrentDateFunction (CURRENT_DATE) is an example of this.

> On Dec 19, 2016, at 12:00 AM, Nagarajan Chinnasamy 
> <[email protected]> wrote:
> 
> Hi,
> 
> Am developing a UDF called SESSION_ID as detailed in issue:
> 
>    https://issues.apache.org/jira/browse/DRILL-5043
> 
> It does not take any input parameters. Now, I can only invoke it using
> parenthesis as in:
> 
>    SELECT SESSION_ID() FROM (Values(1));
> 
> I would like to know what do I need to do if I need to invoke it without
> paranthesis like:
> 
>    SELECT SESSION_ID FROM (Values(1));
> 
> Appreciate your input.
> 
> Best Regards,
> Nagu.

Reply via email to