<p>Table: <code>Orders</code></p> <pre> +-----------------+----------+ | Column Name | Type | +-----------------+----------+ | order_number | int | | customer_number | int | +-----------------+----------+ order_number is the primary key (column with unique values) for this table. This table contains information about the order ID and the customer ID. </pre> <p> </p> <p>Write a solution to find the <code>customer_number</code> for the customer who has placed <strong>the largest number of orders</strong>.</p> <p>The test cases are generated so that <strong>exactly one customer</strong> will have placed more orders than any other customer.</p> <p>The result format is in the following example.</p> <p> </p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> Orders table: +--------------+-----------------+ | order_number | customer_number | +--------------+-----------------+ | 1 | 1 | | 2 | 2 | | 3 | 3 | | 4 | 3 | +--------------+-----------------+ <strong>Output:</strong> +-----------------+ | customer_number | +-----------------+ | 3 | +-----------------+ <strong>Explanation:</strong> The customer with number 3 has two orders, which is greater than either customer 1 or 2 because each of them only has one order. So the result is customer_number 3. </pre> <p> </p> <p><strong>Follow up:</strong> What if more than one customer has the largest number of orders, can you find all the <code>customer_number</code> in this case?</p>