Обсуждение: Accessing structured datatypes using libpq
Hi,
What is the recommended way of accessing structured data-types (especially JSONB and HSTORE) using libpq? It seems that by default JSONB data for example is returned as text.
Is it not possible to have binary access to these data-types? If it is possible, then how do I do it exactly as the only thing I get from libpq is a void-pointer?
Cheers,
Raimo
On 6/10/2014 11:20 PM, Raimo Jormakka wrote: > > What is the recommended way of accessing structured data-types > (especially JSONB and HSTORE) using libpq? It seems that by default > JSONB data for example is returned as text. > > Is it not possible to have binary access to these data-types? If it is > possible, then how do I do it exactly as the only thing I get from > libpq is a void-pointer? those are text data types. there is no binary representations. -- john r pierce 37N 122W somewhere on the middle of the left coast
2014-06-11 9:44 GMT+03:00 John R Pierce <pierce@hogranch.com>:
On 6/10/2014 11:20 PM, Raimo Jormakka wrote:those are text data types. there is no binary representations.
What is the recommended way of accessing structured data-types (especially JSONB and HSTORE) using libpq? It seems that by default JSONB data for example is returned as text.
Is it not possible to have binary access to these data-types? If it is possible, then how do I do it exactly as the only thing I get from libpq is a void-pointer?
Can someone elaborate this a bit? Isn't the key distinction between the JSONB and JSON data-types the fact that the former is a binary format while the latter one is text-based?
On Wed, Jun 11, 2014 at 6:59 PM, Raimo Jormakka <raimo.jormakka@gmail.com> wrote: > 2014-06-11 9:44 GMT+03:00 John R Pierce <pierce@hogranch.com>: > >> On 6/10/2014 11:20 PM, Raimo Jormakka wrote: >>> >>> >>> What is the recommended way of accessing structured data-types >>> (especially JSONB and HSTORE) using libpq? It seems that by default JSONB >>> data for example is returned as text. >>> >>> Is it not possible to have binary access to these data-types? If it is >>> possible, then how do I do it exactly as the only thing I get from libpq is >>> a void-pointer? >> >> >> those are text data types. there is no binary representations. > > > Can someone elaborate this a bit? Isn't the key distinction between the > JSONB and JSON data-types the fact that the former is a binary format while > the latter one is text-based? Internally yes, representation of those data types on disk is different. However the output result, the one obtained by libpq or any client is similar in appearance. -- Michael
On Wed, Jun 11, 2014 at 1:20 AM, Raimo Jormakka <raimo.jormakka@gmail.com> wrote: > Hi, > > What is the recommended way of accessing structured data-types (especially > JSONB and HSTORE) using libpq? It seems that by default JSONB data for > example is returned as text. > > Is it not possible to have binary access to these data-types? If it is > possible, then how do I do it exactly as the only thing I get from libpq is > a void-pointer? check out libpqtypes: http://libpqtypes.esilo.com/. it gives C client side representations of most common types including hstore. jsonb is not supported yet but the library is pluggable to add support for new types. merlin