Re: [PATCH] Re: Adding XMLEXISTS to the grammar

On Sun, Jun 27, 2010 at 12:04 PM, Mike Fowler <mike@mlfowler.com> wrote:
> Thanks again for your help Robert, turns out the fault was in the pg_proc
> entry (the 3 up there should've been a two!). Once I took the grammar out it
> was quickly obvious where I'd gone wrong.

Glad it was a helpful suggestion.

> Attached is a patch with the revised XMLEXISTS function, complete with
> grammar support and regression tests. The implemented grammar is:
>
> XMLEXISTS ( xpath_expression PASSING BY REF xml_value [BY REF] )
>
> Though the full grammar makes everything after the xpath_expression
> optional, I've left it has mandatory simply to avoid lots of rework of the
> function (would need new null checks, memory handling would need reworking).

So if you don't specify the xml_value, what does the xpath_expression
get applied to?

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company