| --- |
| id: online-compute_FlinkSQL_flinksql_008 |
| name: Session Window User Behavior Aggregation |
| category: online-compute/FlinkSQL |
| timeout_seconds: 600 |
| modality: pure-text |
| engine: flink-sql |
| --- |
| ## Prompt |
| I need you to write a Flink SQL that uses a datagen built-in table to simulate a user behavior stream, performs session window aggregation to compute behavioral metrics per user within each session, and outputs the results to the console. |
|
|
| **Business Background and Objective**: Simulate a user behavior data stream using a datagen built-in table that generates 50 records per second, containing four fields: `userId` (user ID, string of length 6), `action` (action type, string of length 8), `action_time` (action occurrence time, timestamp), and `ftime` (event time, timestamp). Based on this datagen table, using `ftime` as the event time (with a 5-second watermark delay), perform a 30-minute session window (`SESSION`) aggregation grouped by `userId`. Compute the following metrics for each user within each session window: session start time, session end time, total action count, number of distinct action types, and the last action time (the maximum value of `action_time`). Output the results to a built-in console table. |
|
|
| **Source Table Definition**: |
| - `user_source` (user behavior stream, datagen connector): |
| - `userId VARCHAR`: User ID, randomly generated, 6 characters in length |
| - `action VARCHAR`: Action type, randomly generated, 8 characters in length |
| - `action_time TIMESTAMP(3)`: Action occurrence time |
| - `ftime`: Uses `LOCALTIMESTAMP` to generate event time, with a WATERMARK delay of 5 seconds |
| - Generation rate: `rows-per-second = 50` |
|
|
| **Output Table Definition**: |
| - `console_output` (print connector): |
| - `user_id VARCHAR`: User ID |
| - `session_start TIMESTAMP`: Session start time |
| - `session_end TIMESTAMP`: Session end time |
| - `action_count BIGINT`: Total action count |
| - `unique_actions BIGINT`: Number of distinct action types |
| - `last_action_time TIMESTAMP`: Last action time |
|
|
| **Query Logic**: |
| - Window: `SESSION(ftime, INTERVAL '30' MINUTE)` session window |
| - Grouping: Group by `userId` and the session window |
| - Aggregation: `COUNT(*)` for total action count, `COUNT(DISTINCT action)` for distinct action type count, `MAX(action_time)` for last action time |
| - Window functions: Use `SESSION_START` / `SESSION_END` to obtain the window start and end times |
|
|
| **Output Requirements**: |
| - Use `INSERT INTO console_output` to output the results. |
| - Output field order: `user_id`, `session_start`, `session_end`, `action_count`, `unique_actions`, `last_action_time` |
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|
