To get column name in the result in postgresql - sql

Question

In the below query I am getting the values in a array format and I want to get column name too.
CREATE OR REPLACE FUNCTION load_page(IN _session integer)
RETURNS TABLE(col1 text, col2 text) AS
$BODY$
BEGIN
RETURN QUERY
select
(SELECT array_agg(sq.*)
FROM (SELECT user_id, user_name
FROM "user"
) sq
)::text,
(SELECT array_agg(sq.*)
FROM (SELECT client_id, client_name ,client_desc
FROM "clients"
) sq
)::text;
END;
$BODY$ LANGUAGE plpgsql STABLE;
The Result is :
"("{""(2,Test)"",""(5,Santhosh)"",""(3,Test1)""}","{""(1,Test1,Test1)"",""(2,test2,test2)"",""(3,test3,test3)""}")"

Answer 1

You could simply type them and concat into one column to use it as a row in outer select:
CREATE OR REPLACE FUNCTION load_page(IN _session integer)
RETURNS TABLE(col1 text, col2 text) AS
$BODY$
BEGIN
RETURN QUERY
select
(SELECT array_agg(sq.*)
FROM (SELECT concat('user_id: ',user_id,', user_name: ', user_name)
FROM "user"
) sq
)::text,
(SELECT array_agg(sq.*)
FROM (SELECT concat('client_id: ',client_id,', client_name: ',client_name,', client_desc: ',client_desc)
FROM "clients"
) sq
)::text;
END;
$BODY$ LANGUAGE plpgsql STABLE;
If you want to discard information about particular column if it's value is NULL you can append column names conditionally (with a CASE statement).

Answer 2

The below function does not produce the curly braces or the flood of double quotes, but it does include the column names and it is quite a bit more concise and readable and efficient than your initial version.
The _session parameter is never used, but I shall assume that this is all part of some larger query/function.
CREATE OR REPLACE FUNCTION load_page(IN _session integer, OUT col1 text, OUT col2 text)
RETURNS SETOF record AS $BODY$
BEGIN
SELECT string_agg('user_id: ' || user_id ||
', user_name: ' || user_name, ',')
INTO col1
FROM "user";
SELECT string_agg('client_id: ' || client_id ||
', client_name: ' || client_name ||
', client_desc: ' || client_desc, ',')
INTO col2
FROM "clients";
RETURN NEXT;
END;
$BODY$ LANGUAGE plpgsql STABLE;