PostgreSQL：不能一行输出JSON值

大家好。

我在如何将 JSON 中的密钥收集到一行（进行连接）时遇到问题。

请求是这样的：

WITH all_values AS (
    SELECT s.projectid AS projectid,
           s.prompttype AS prompttype,
           (s.attributes::jsonb)->>'prompt' AS prompt,
           (s.attributes::jsonb)->>'description' AS description,
           (s.attributes::jsonb)->>'topic' AS topic,
           (s.attributes::jsonb)->>'context' AS context,
           (s.attributes::jsonb)->>'use_case' AS use_case,
           (s.attributes::jsonb)->>'subtitle' AS subtitle,
           (s.attributes::jsonb)->>'txValues' AS txValues,
           (s.attributes::jsonb)->>'flashmode' AS flashmode,
           (s.attributes::jsonb)->>'skippable' AS skippable,
           (s.attributes::jsonb)->>'videoMaxDuration' AS videoMaxDuration,
           (s.attributes::jsonb)->>'defaultCameraFacing' AS defaultCameraFacing,
           s.corpuscode AS corpuscode,
           s.scriptid AS scriptid,
           s.promptnum AS promptnum,
           SELECT ARRAY_AGG(f) 
               FROM (
                   SELECT jsonb_object_keys(attributes::jsonb) f
                   FROM source_table
           ) AS u
    FROM source_table AS s
    WHERE
        s.prompttype != 'input' AND (s.created > now() - interval '30 minutes' OR s.modified > now() - interval '30 minutes')
    GROUP BY s.projectid, s.prompttype, prompt, description, topic, context, use_case, subtitle, txValues, flashmode, skippable, videoMaxDuration, defaultCameraFacing, corpuscode, scriptid, promptnum
   )
SELECT * FROM all_values;

错误：错误：“SELECT”第 18 行或附近的语法错误：SELECT ARRAY_AGG(f)

我这样检查：

SELECT ARRAY_AGG(f) 
FROM (
  SELECT jsonb_object_keys(attributes::jsonb) f
  FROM source_table
) AS u;

并获得输出。

在这里测试：https ://dbfiddle.uk/?rdbms=postgres_9.6&fiddle=dcf7722ab857c13c2d3c8edf172b434e

PS 理想情况下，在这个输出中，我不需要过滤所有的键，而只需要过滤其中的一部分，但这是下一个问题......