Get data from jsonb field array

Question

I have the following schema in PostgreSQL database:

CREATE TABLE survey_results (
    id integer NOT NULL,
    raw jsonb DEFAULT '{}'::jsonb,
    created_at timestamp without time zone,
    updated_at timestamp without time zone  
);

INSERT INTO survey_results (id, raw, created_at, updated_at)
    VALUES (1, '{ "slides": [{"id": "1", "name": "Test", "finished_at": 1517421628092}, {"id": "2", "name": "Test", "finished_at": 1517421894736}]}', now(), now());

I want to get data from raw['slides']. I want to have query which return every raw['slides'] id and raw['slides'] finished_at. So result of a query should look like this:

id  finished_at
1 1517421628092
2 1517421894736

Here is sqlfiddle to experiment with:

http://sqlfiddle.com/#!17/ae504

How can I do this in PostgreSQL?

Answer 1

You need to unnest the array, then you can access each element:

select s.slide ->> 'id' as id,
       s.slide ->> 'finished_at' as finished_at
from survey_results, jsonb_array_elements(raw -> 'slides') as s (slide)

http://sqlfiddle.com/#!17/ae504/80

For more details see JSON Functions and Operators in the manual.