pg Table Foreign Key Relations, includes composite PKs

gistfile1.sql

SELECT 
    tc.constraint_name key_name,
    ctu.table_name parent_table,
    tc.table_name child_table,  
	(SELECT kcu2.column_name 
	    FROM information_schema.table_constraints tc2
		INNER JOIN information_schema.Key_column_usage kcu2
		ON tc2.table_name = kcu2.table_name AND tc2.constraint_name = kcu2.constraint_name
	    WHERE tc2.constraint_type = 'PRIMARY KEY' AND tc2.table_name = ctu.table_name) parent_id,
        (SELECT kcu.column_name
            FROM information_schema.key_column_usage kcu
            WHERE kcu.constraint_name = tc.constraint_name AND kcu.table_name = tc.table_name) child_id
FROM information_schema.table_constraints tc 
INNER JOIN information_schema.constraint_table_usage ctu
ON ctu.constraint_name = tc.constraint_name
WHERE tc.constraint_type = 'FOREIGN KEY';