Re: json api WIP patch

Andrew Dunstan <andrew@dunslane.net>

From: Andrew Dunstan <andrew@dunslane.net>
To: Merlin Moncure <mmoncure@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2013-01-15T00:52:56Z
Lists: pgsql-hackers
On 01/14/2013 07:36 PM, Merlin Moncure wrote:
> While testing this I noticed that integer based 'get' routines are
> zero based -- was this intentional?  Virtually all other aspects of
> SQL are 1 based:
>
> postgres=# select json_get('[1,2,3]', 1);
>   json_get
> ----------
>   2
> (1 row)
>
> postgres=# select json_get('[1,2,3]', 0);
>   json_get
> ----------
>   1
> (1 row)
>


Yes. it's intentional. SQL arrays might be 1-based by default, but 
JavaScript arrays are not. JsonPath and similar gadgets treat the arrays 
as zero-based. I suspect the Json-using community would not thank us for 
being overly SQL-centric on this - and I say that as someone who has 
always thought zero based arrays were a major design mistake, 
responsible for countless off-by-one errors.

cheers

andrew