从PostgreSQL中的jsonb数组中获取一个元素

我的PostgreSQL数据库中有以下架构:

CREATE TABLE survey_results (
    id integer NOT NULL
);

CREATE TABLE slide_results (
    id integer NOT NULL,
    survey_result_id integer,
    buttons jsonb DEFAULT '[]'::jsonb
);

INSERT INTO survey_results (id)
  VALUES (1);

INSERT INTO slide_results (id, survey_result_id, buttons)
  VALUES (1, 1, '[{"text": "Not at all"}, {"text": "Yes"}]');

INSERT INTO slide_results (id, survey_result_id, buttons)
  VALUES (2, 1, '[{"text": "No"}, {"text": "Yes"}]');

WITH data AS ( 
  select 
    sr.id ,
    jsonb_agg(row_to_json(slr)) AS json_row
  from slide_results slr
  INNER JOIN survey_results sr ON sr.id = slr.survey_result_id
  group by sr.id
)

SELECT id, json_row->0->>'buttons' from data;

返回:

| id  | ?column?                                  |
| --- | ----------------------------------------- |
| 1   | [{"text": "Not at all"}, {"text": "Yes"}] |

我希望此查询只返回buttons数组的第一个元素。我试过这样的方法:

WITH data AS ( 
  select 
    sr.id ,
    jsonb_agg(row_to_json(slr)) AS json_row
  from slide_results slr
  INNER JOIN survey_results sr ON sr.id = slr.survey_result_id
  group by sr.id
)

SELECT id, json_row->0->>'buttons'->>1 from data;

Query Error: error: operator does not exist: text ->> integer

我怎样才能解决这个问题?

https://www.db-fiddle.com/f/gP761psywgmovfdTT7DjP4/1