连接 JSON 行

Question

我有以下 table 示例记录：

create table jtest
(
    id int,
    jcol json
);

insert into jtest values(1,'{"name":"Jack","address1":"HNO 123"}');
insert into jtest values(1,'{"address2":"STREET1"}');
insert into jtest values(1,'{"address3":"UK"}');

select * from jtest;

id      jcol
-------------------------------------------
1       {"name":"Jack","address":"HNO 123 UK"}
1       {"address2":"STREET1"}
1       {"address3":"UK"}

预期结果：

id      jcol
--------------------------------------------------------------------------------------------
1       {"name":"Jack","address":"HNO 123 UK", "address2":"STREET1", "address3":"UK"}

尝试了以下查询：

select id,json_agg(jcol) as jcol
from jtest
group by id;

但是得到的结果出乎意料：

id      jcol
--------------------------------------------------------------------------------------------
1       [{"name":"Jack","address":"HNO 123 UK"}, {"address2":"STREET1"}, {"address3":"UK"}]

Answer 1

demo:db<>fiddle

SELECT
    id,
    json_object_agg(key, value)      -- 2
FROM
    t,
    json_each(jcol)                  -- 1
GROUP BY id

首先你必须将所有元素提取到一行中
之后您可以重新聚合所有这些

连接 JSON 行

Concatenate JSON rows

postgresql

postgresql-10