On Fri, Apr 8, 2016 at 8:53 AM, Raymond O'Donnell <rod@iol.ie> wrote:
On 08/04/2016 16:31, Michael Nolan wrote: > I'm looking at the possibility of using JSON as a data exchange format > with some apps running on both PCs and Macs. . > > The table I would be exporting has a lot of NULL values in it. Is > there any way to skip the NULL values in the row_to_json function and > include only the fields that are non-null?
You could use a CTE to filter out the nulls (not tested - I haven't used JSON in PG (yet!)):
with no_nulls as ( select ... from my_table where whatever is not null ) select row_to_json(....) from no_nulls;
One of us is confused. I'm reading this as "I want a row_to_json" call to generate objects with different keys depending on whether a given key would have a null - in which case exclude the key.
I
think one would have to simply allow row_to_json to populate the keys with null values and then post-process them away:
