| --- |
| id: online-compute_FlinkSQL_flinksql_011 |
| name: Tumbling Window Product TopN Ranking |
| category: online-compute/FlinkSQL |
| timeout_seconds: 600 |
| modality: pure-text |
| engine: flink-sql |
| --- |
| ## Prompt |
| I need you to write a Flink SQL that uses the built-in datagen connector to simulate an order data source, aggregates product sales over a 10-minute tumbling window, and then uses the `ROW_NUMBER` window function to retrieve the top 5 products by sales within each window, outputting the results to the console. |
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| **Business Background and Objective**: Simulate an order stream using a datagen built-in table, generating massive order data. Group by a 10-minute tumbling window to compute the total sales amount and order count per product within each window, and finally use `ROW_NUMBER` ranking to retrieve the top 5 products by sales amount within each window. |
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| **Source Table Definition**: |
| - `order_source` (order stream, datagen connector): |
| - `order_id BIGINT`: Order ID, randomly generated in the range 1–10,000,000 |
| - `product_id INT`: Product ID, randomly generated in the range 1–200 |
| - `amount DOUBLE`: Order amount, randomly generated in the range 0–500 |
| - `event_time`: Uses `LOCALTIMESTAMP` to generate event time, with a WATERMARK delay of 5 seconds |
| - Generation rate: `rows-per-second = 8000` |
|
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| **Output Table Definition**: |
| - `console_output` (print connector): |
| - `window_start TIMESTAMP(3)`: Tumbling window start time |
| - `product_id INT`: Product ID |
| - `sales DOUBLE`: Total sales amount of the product within the window |
| - `order_cnt BIGINT`: Number of orders for the product within the window |
| - `rn BIGINT`: Sales ranking within the window |
|
|
| **SQL Logic**: |
| - Apply `TUMBLE(event_time, INTERVAL '10' MINUTE)` tumbling window on `order_source` |
| - Group by `window_start`, `window_end`, `product_id` |
| - Aggregate `SUM(amount) AS sales` and `COUNT(*) AS order_cnt` |
| - Use `ROW_NUMBER() OVER (PARTITION BY window_start, window_end ORDER BY sales DESC) AS rn` |
| - Outer query filter: `WHERE rn <= 5` |
| - Final SELECT: `window_start`, `product_id`, `sales`, `order_cnt`, `rn` |
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| **Output Requirements**: |
| - Use `INSERT INTO console_output` to output the results. |
| - Output field order: `window_start`, `product_id`, `sales`, `order_cnt`, `rn` |
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