将查询结果转换为postgresql中的一个数组json对象

Question

My problem is that I want to convert the query result to be one json object in Postgresql

For example, I have a query like this:

SELECT row_to_json(r)
FROM 
(
    select ff.*, json_agg(ffo."option") as options
    from form_field ff, form_field_options ffo 
    where ffo.form_field_id = ff.id and ff.form_id = 'fef5c7e0-170c-4556-80d2-42e3db66cfa2'
    group by ff.id
) r

And the result is:

Is there anyway to convert the result to be something like: [{...}, {...}] so I can use it as a sub query in another query

Thanks for reading <3

Answer 1

you can add another layer of json_agg to convert it to a list of json objects.

eg

SELECT json_agg(row_to_json(r)) my_json_data
FROM 
(
    select ff.*, json_agg(ffo."option") as options
    from form_field ff, form_field_options ffo 
    where ffo.form_field_id = ff.id and ff.form_id = 'fef5c7e0-170c-4556-80d2-42e3db66cfa2'
    group by ff.id
) r