我在我的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"}]');
并且以下查询:
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"}] |
我希望这个查询仅返回buttons数组的第一个元素。我尝试了以下内容:
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;
但是这个给我返回了一个错误:
Query Error: error: operator does not exist: text ->> integer
我应该怎么修复它?