Re: BUG #7620: array_to_json doesn't support heterogeneous arrays

On Tue, Oct 23, 2012 at 8:05 PM, Greg Hazel <ghazel(at)gmail(dot)com> wrote:
> On Oct 23, 2012, at 6:03 PM, Merlin Moncure <mmoncure(at)gmail(dot)com> wrote:
>
>> On Tue, Oct 23, 2012 at 6:32 PM, <ghazel(at)gmail(dot)com> wrote:
>>> The following bug has been logged on the website:
>>>
>>> Bug reference: 7620
>>> Logged by: Greg Hazel
>>> Email address: ghazel(at)gmail(dot)com
>>> PostgreSQL version: 9.2.1
>>> Operating system: Amazon Linux
>>> Description:
>>>
>>> array_to_json(ARRAY['foo', 100, true]) complains because arrays can't have
>>> mixed types, but json arrays can.
>>>
>>> So, it's not possible to form a heterogeneous json array, when this is often
>>> desired.
>>
>> This is not really a bug because the feature is working as intended.
>> Postgres arrays are homogonous so what you're asking really isn't
>> possible. You can though use row_to_json to work around:
>>
>> select row_to_json(row('foo', 100, true));
>
> That doesn't produce the same results.
>
> Call it a feature request or a bug report, the postgres json support fails to make the json I need.

I didn't say that it did: what it does is return a javascript object
which is only a very little bit different from an array. For example,
you can do jquery each() over either. I guess if you had to have an
array, you could do it like this:

array_to_json(ARRAY['foo'::text, 100::text, true::text])

merlin