Re: JSON NULLs

On 2013-02-08 15:15, Andrew Dunstan wrote:
>
>
>
> Revised patch attached. The problem also existed with the get*_as_text 
> functions (and their operators). Some additional regression tests are 
> added to test these cases.

Hi,

I did some minor things with the patch today.

1. thanks for the work on the json type, great to see it in Postgres and 
also more functions on it!

2.
during compile on

jsonfuncs.c: In function `each_object_field_end':
jsonfuncs.c:1151:13: warning: assignment makes integer from pointer 
without a cast

yeb@unix:~/ff$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 
4.5.2-8ubuntu4' --with-bugurl=file:///usr/share/doc/gcc-4.5/README.Bugs 
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr 
--program-suffix=-4.5 --enable-shared --enable-multiarch 
--with-multiarch-defaults=x86_64-linux-gnu --enable-linker-build-id 
--with-system-zlib --libexecdir=/usr/lib/x86_64-linux-gnu 
--without-included-gettext --enable-threads=posix 
--with-gxx-include-dir=/usr/include/c++/4.5 
--libdir=/usr/lib/x86_64-linux-gnu --enable-nls --with-sysroot=/ 
--enable-clocale=gnu --enable-libstdcxx-debug 
--enable-libstdcxx-time=yes --enable-plugin --enable-gold 
--enable-ld=default --with-plugin-ld=ld.gold --enable-objc-gc 
--disable-werror --with-arch-32=i686 --with-tune=generic 
--enable-checking=release --build=x86_64-linux-gnu 
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu4)

3. I was wondering how to access the first author from this json snippet:

{ "id": "QZr82w_eSi8C", "etag": "KZ+JsrkCdqw", "volumeInfo": {  "title": "Heads Up Software Construction",  "authors":
[  "Dan Malone",   "Dave Riles"  ],
 


and played a bit with json_get_path_as_text(document,  'volumeInfo', 
'authors') that accepts a list of keys as arguments. Have you thought 
about an implementation that would accept a single path argument like 
'volumeInfo.authors[0]' ? This might be more powerful and easy to use, 
since the user does not need to call another function to get the first 
element from the author array, and the function call does not need to be 
changed when path lenghts change.

My apologies if this has been discussed before - I've gone through 
threads from nov 2012 but did not find a previous discussion about this 
topic.

regards,
Yeb Havinga