Postgres JSON函数与group by

Question

表：

TimeLimiter

http://sqlfiddle.com/#!17/04630/4

查询我尝试过：

Lazy

我希望按CREATE TABLE profit_center ( id serial NOT NULL, name character varying, site_id integer, CONSTRAINT profit_center_pkey PRIMARY KEY (id), CONSTRAINT profit_center_name_site_id_key UNIQUE (name, site_id) ); 的所有select site_id,json_build_object(name,id) as jsn from profit_center; 值进行分组。单行预期结果：

jsn

Answer 1

看起来很糟糕，但是returns your expected result：

with r as (select concat('"',site_id,'": ',concat('{',string_agg(concat('"',name,'": ',id),','),'}')::json) from profit_center group by site_id)
select concat('{',string_agg(concat,','),'}')::json from r;