How to get only the jsonb of specific keys from postgres?

Question

I\'m aware that you can remove keys from a jsonb in postgres using something like this

select \'{\"a\": 1, \"b\": 2, \"c\":3}\'::jsonb -\'a\';
 ?column?
--------         


        

Answer 1

You can filter down to a single key fairly easily like so:

jsonb_object(ARRAY[key, jsonb_data -> key])

...or you can filter down to multiple keys:

(SELECT jsonb_object_agg(key, value) FROM jsonb_each(jsonb_data) WHERE key IN ('a', 'b'))

Or on a more complex condition, if you want:

(
  SELECT jsonb_object_agg(key, value)
  FROM jsonb_each(jsonb_data)
  WHERE
    key NOT LIKE '__%'
    AND jsonb_typeof(value) != 'null'
)

These kinds of questions can be answered very easily by simply reading the documentation.