Customer Placing the Largest Number of Orders
<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>&nbsp;</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>&nbsp;</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>&nbsp;</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>

[]
['Create table If Not Exists orders (order_number int, customer_number int)', 'Truncate table orders', "insert into orders (order_number, customer_number) values ('1', '1')", "insert into orders (order_number, customer_number) values ('2', '2')", "insert into orders (order_number, customer_number) values ('3', '3')", "insert into orders (order_number, customer_number) values ('4', '3')"]
[{"value": "mysql", "text": "MySQL", "defaultCode": "# Write your MySQL query statement below\n"}, {"value": "mssql", "text": "MS SQL Server", "defaultCode": "/* Write your T-SQL query statement below */\n"}, {"value": "oraclesql", "text": "Oracle", "defaultCode": "/* Write your PL/SQL query statement below */\n"}, {"value": "pythondata", "text": "Pandas", "defaultCode": "import pandas as pd\n\ndef largest_orders(orders: pd.DataFrame) -> pd.DataFrame:\n    "}, {"value": "postgresql", "text": "PostgreSQL", "defaultCode": "-- Write your PostgreSQL query statement below\n"}]
{"mysql": ["Create table If Not Exists orders (order_number int, customer_number int)"], "mssql": ["Create table orders (order_number int, customer_number int)"], "oraclesql": ["Create table orders (order_number int, customer_number int)"], "database": true, "name": "largest_orders", "pythondata": ["orders = pd.DataFrame([], columns=['order_number', 'customer_number']).astype({'order_number':'Int64', 'customer_number':'Int64'})"], "postgresql": ["Create table If Not Exists orders (order_number int, customer_number int)"], "database_schema": {"orders": {"order_number": "INT", "customer_number": "INT"}}}
{"mysql": ["MySQL", "<p><code>MySQL 8.0</code>.</p>"], "mssql": ["MS SQL Server", "<p><code>mssql server 2019</code>.</p>"], "oraclesql": ["Oracle", "<p><code>Oracle Sql 11.2</code>.</p>"], "pythondata": ["Pandas", "<p>Python 3.10 with Pandas 2.2.2 and NumPy 1.26.4</p>"], "postgresql": ["PostgreSQL", "<p>PostgreSQL 16</p>"]}
['Database']