JSON "pretty" and selecting nested JSON fields

[Deven Phillips <deven.phillips@xxxxxxxxx>]

Hi all,

    I have a query which selects several rows of data, and contained in one of those rows is some aggregated JSON data. I am using row_to_json() to make the whole output JSON and I am providing "true" for pretty formatting of the JSON. The problem that I am seeing is that they nested JSON block is not being prettified along with the outer JSON.

Example:

I have a function which takes a single key param and returns a JSON array:

CREATE OR REPLACE FUNCTION get_virtual_interfaces(vm_id BIGINT) RETURNS jsonb AS $$
DECLARE
    res jsonb;
BEGIN
SELECT array_to_json(array_agg(row_to_json(i, true)), true)
        FROM (
            SELECT DISTINCT * FROM virtual_interfaces WHERE vmid=vm_id) i INTO res;
    RETURN res;
END;
$$ LANGUAGE PLPGSQL;

That function is then used in another query to provide a nested JSON containing the array:

SELECT
    row.snt_code AS "snt_code",
    row.vdc AS "vdc",
    row.uuid AS "uuid",
    row_to_json(row, true) AS "json"
FROM (
    SELECT
        vm.*,
        CONCAT('https://int.cloudcontrol.sgns.net/v3/customer/', vm.snt_code, '/vdc/', vm.vdc, '/vm/', vm.uuid) AS "self",
        'cc.v3.sungardas.vm' AS "type",
        (get_virtual_interfaces(vm.vmid)) as interfaces
    FROM virtual_machines vm
) row;

The outer level of JSON is "pretty printed", but the content of the array from the function is NOT, even though I have specified that it should be. Any suggestions of how to address this?

Thanks in advance!

Deven