Re: Functions and Parentheses

On Fri, Oct 6, 2017 at 2:18 PM, Igal @ Lucee.org <igal(at)lucee(dot)org> wrote:

> Hi,
>
> Is current_date a function? It's a bit puzzling to me since there are no
> parentheses after it, i.e.
>
> SELECT current_date;
>
> And not
>
> SELECT current_date(); -- syntax error
>
​
It, and the others like it, behave as functions. They don't require
parentheses because the SQL standard​
​
​ defines them without parentheses.

> How come `current_date` has no parenthesis but `clock_timestamp()` does?
>
clock_timestamp isn't standard defined and unless the standard forces us to
do otherwise function invocation requires parentheses.

See 9.9.4 (
https://www.postgresql.org/docs/9.6/static/functions-datetime.html )

David J.