Show the order ids and the number of invoices for each order.
SELECT order_id ,  count(*) FROM Invoices GROUP BY order_id
SELECT order_id ,  count(*) FROM Invoices GROUP BY order_id
[{'order_id': 3, 'count(*)': 3}, {'order_id': 4, 'count(*)': 1}, {'order_id': 5, 'count(*)': 1}, {'order_id': 8, 'count(*)': 1}, {'order_id': 9, 'count(*)': 3}, {'order_id': 10, 'count(*)': 2}, {'order_id': 11, 'count(*)': 1}, {'order_id': 12, 'count(*)': 1}, {'order_id': 13, 'count(*)': 1}, {'order_id': 14, 'count(*)': 1}]