jsonb_path_query 按 child 订购

Question

我有一个嵌套的 json 结构

{
  "feed": {
    "3": {
       "id1": {
          "id": "activity-1",
          "created": 1469905513973,
          "verb": "added recipe 1"
       },
       "id2": {
          "id": "activity-2",
          "created": 1470013085119,
          "verb": "added recipe 2"
       },
       "id3": {
          "id": "activity-3",
          "created": 1472341861543,
          "verb": "added recipe 3"
       }
    }
  }
}

我想 select /feed/3 中的所有内容并按 created 订购。

我一直想不出正确的语法。

SELECT jsonb_path_query(
    '{ "feed": { "3": { "id1": { "id": "activity-1", "created": 1469905513973, "verb": "added recipe 1" }, "id2": { "id": "activity-2", "created": 1470013085119, "verb": "added recipe 2" }, "id3": { "id": "activity-3", "created": 1472341861543, "verb": "added recipe 3" } } } }',
     '$."feed"."3".*')
 order by "created" desc;

这个版本给了我一个ERROR: column "created" does not exist

没有 order by 子句，输出看起来像

# SELECT jsonb_path_query('{ "feed": { "3": { "id1": { "id": "activity-1", "created": 1469905513973, "verb": "added recipe 1" }, "id2": { "id": "activity-2", "created": 1470013085119, "verb": "added recipe 2" }, "id3": { "id": "activity-3", "created": 1472341861543, "verb": "added recipe 3" } } } }', '$."feed"."3".*');
                             jsonb_path_query                             
--------------------------------------------------------------------------
 {"id": "activity-1", "verb": "added recipe 1", "created": 1469905513973}
 {"id": "activity-2", "verb": "added recipe 2", "created": 1470013085119}
 {"id": "activity-3", "verb": "added recipe 3", "created": 1472341861543}
(3 rows)

我很确定 jsonb_path_query 中的 side-effect 返回了一组，但我不知道如何处理它。感谢您的帮助！

Answer 1

您的结果不包含名为 created 的列，仅包含包含 JSON 值的名为 jsonb_path_query 的列。

您需要从 JSON 中提取数字才能对其进行排序。还建议在 FROM 子句中使用集合返回函数：

SELECT *
FROM jsonb_path_query('{...}', '$."feed"."3".*') as t(item)
order by (item ->> 'created')::bigint desc;

jsonb_path_query 按 child 订购

jsonb_path_query with order by child

postgresql

jsonb