如何对使用 json 聚合的子查询的结果进行排序?
如果我有这样的模式:
CREATE TABLE plans( id integer NOT NULL, name character varying(255));
CREATE TABLE plan_items ( id integer NOT NULL, plan_id integer NOT NULL, expected_at date, status integer);
我正在通过子查询将 plan_items 结果聚合到 json 列上。 像这样:
SELECT
plans.id,
plans.name,
jsonb_agg((SELECT pi_cols FROM
(SELECT plan_items.id, plan_items.expected_at, plan_items.status) pi_cols
)) AS plan_items_data
FROM
plans
INNER JOIN plan_items ON plan_items.plan_id = plans.id
GROUP BY
plans.id,
plans.name
ORDER BY plans.id;
JSON 聚合按预期工作,并为我提供了我需要的结果。好的。 但我无法订购结果。
我试过:
jsonb_agg((SELECT pi_cols FROM
(SELECT plan_items.id, plan_items.expected_at, plan_items.status ORDER BY plan_items.expected_at) pi_cols
)) AS plan_items_data
还有:
jsonb_agg((SELECT pi_cols FROM
(SELECT plan_items.id, plan_items.expected_at, plan_items.status) pi_cols ORDER BY pi_cols.expected_at
)) AS plan_items_data
但这些都没有解决。
有什么想法吗?
最佳答案
作为Abelisto建议,只需使用一个简单的 aggregate expression with ordering :
jsonb_agg(plan_items ORDER BY plan_items.expected_at) AS plan_items_data
关于json - Postgresql jsonb_agg 子查询排序,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/40652871/