OneNoughtOne
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You are given transactional data from an online ordering system.
Table Orders has one row per order:
Your task is to return the customer_number of the customer who placed the highest number of orders.
The test data guarantees exactly one customer has a strictly higher order count than every other customer.
Output requirements:
Submissions are supported in:
Orders:
| order_number | customer_number |
|--------------|-----------------|
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 3 |[{"customer_number":3}]Explanation
Customer 3 appears twice, while customers 1 and 2 appear once each.
Orders:
| order_number | customer_number |
|--------------|-----------------|
| 10 | 42 |
| 11 | 42 |
| 12 | 11 |
| 13 | 11 |
| 14 | 42 |
| 15 | 7 |[{"customer_number":42}]Explanation
Customer 42 has three orders, which is more than all others.
Orders:
| order_number | customer_number |
|--------------|-----------------|
| 100 | 9001 |[{"customer_number":9001}]Explanation
With one recorded order, customer 9001 is trivially the top customer.
Constraints