Re: [GENERAL] Stability of JSON textual representation
On Mon, Feb 9, 2015 at 3:07 AM, David Evans david.ev...@cantab.net wrote: On 9 February 2015 at 03:57, Gavin Flower gavinflo...@archidevsys.co.nz wrote: Would using jsonb be more consistent? Yes, casting to jsonb seems produce consistent output: # SELECT array_to_json(array[1, 2, 3])::jsonb, json_build_array(1, 2, 3)::jsonb; array_to_json | json_build_array ---+-- [1, 2, 3] | [1, 2, 3] That makes sense I suppose, given that only the structure in preserved in the jsonb representation. This is not really due to whitespace/'structure only' preservation aspects of json and jsonb, respectively. What is happening here is that the various functions that render json from text are non consistent in terms of spacing. Personally, I greatly prefer the xxx_to_json functions because they don't insert spurious whitespace making for more compact documents; putting in spaces for aesthetic purposes is the job for a prettifier. merlin -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] Stability of JSON textual representation
On 9 February 2015 at 03:57, Gavin Flower gavinflo...@archidevsys.co.nz wrote: Would using jsonb be more consistent? Yes, casting to jsonb seems produce consistent output: # SELECT array_to_json(array[1, 2, 3])::jsonb, json_build_array(1, 2, 3)::jsonb; array_to_json | json_build_array ---+-- [1, 2, 3] | [1, 2, 3] That makes sense I suppose, given that only the structure in preserved in the jsonb representation. Thanks! I should have thought of that myself. Dave
[GENERAL] Stability of JSON textual representation
I've noticed that when representing lists as JSON, Postgres 9.4 sometimes outputs spaces after commas, and other times does not. # SELECT array_to_json(array[1, 2, 3]), json_build_array(1, 2, 3); array_to_json | json_build_array ---+-- [1,2,3] | [1, 2, 3] This matters to me because I'm intending the hash the JSON text and use the hash for change detection. This difference in behaviour doesn't seem to be documented anywhere. Does anyone know whether it is likely to be stable? Many thanks, Dave
Re: [GENERAL] Stability of JSON textual representation
I've noticed that when representing lists as JSON, Postgres 9.4 sometimes outputs spaces after commas, and other times does not. Here is a similar test on 9.3: # select '[1,2,3]'::json::text, '[1, 2, 3]'::json::text; text | text -+--- [1,2,3] | [1, 2, 3] It looks like even casting back and forth between text and json preserves the text. Paul -- _ Pulchritudo splendor veritatis. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] Stability of JSON textual representation
On 03/02/15 00:06, David Evans wrote: I've noticed that when representing lists as JSON, Postgres 9.4 sometimes outputs spaces after commas, and other times does not. # SELECT array_to_json(array[1, 2, 3]), json_build_array(1, 2, 3); array_to_json | json_build_array ---+-- [1,2,3] | [1, 2, 3] This matters to me because I'm intending the hash the JSON text and use the hash for change detection. This difference in behaviour doesn't seem to be documented anywhere. Does anyone know whether it is likely to be stable? Many thanks, Dave Would using jsonb be more consistent? Cheers, Gavin -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
