On 11/30/2012 10:04 AM, Hannu Krosing wrote:


OK, so based on this discussion, I'm thinking of the following:

 * keep the original functions and operators. json_keys is still
   required for the case where the json is not flat.
 * json_each(json) => setof (text, text)
   errors if the json is not a flat object

Why not json_each(json) => setof (text, json) ? with no erroring out ?

if the json does represent text it is easy to convert to text on the query side.


Well, it would be possible, sure. I'm not sure how useful. Or we could do both fairly easily. It's not as simple or efficient as you might think to dequote / de-escape json string values, which is why the original API had variants for returning both types of values. Maybe we need a function for doing just that.


 * json_unnest(json) => setof json
   errors if the json is not an array
 * json_unnest_each => setof (int, text, text)
   errors if the array is not an array of flat objects
json_unnest_each => setof (int, text, json)

ditto.

 * populate_record(record, json) => record
   errors if the json isn't a flat object
errors if the values are not castable to records field types

nb! some nonflatness is castable. especially to json or hstore or record types


If the record has a json field, certainly. If it has a record field, fairly likely. hstore could probably be a problem given it's not a core type. Similarly to the generation functions discussed in another thread, I could possibly look up a cast from json to the non-core type and use it. That might work for hstore.

I'll try to keep this as permissive as possible.


 * populate_recordset(record, json) => setof record
   errors if the json is not an array of flat objects
ditto

ditto ;-)


cheers

andrew



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