
At StreamForge, product analysts want to identify users who completed action A but did not complete action B within the next 24 hours. Write a PostgreSQL query to return those users.
A event independently.A event with no corresponding B event from the same user in the next 24 hours.A event.a_timestamp ascending, then user_id ascending.| Table | Column | Type | Description |
|---|---|---|---|
| users | user_id | INT | Unique user identifier |
| users | user_name | VARCHAR(100) | User display name |
| users | signup_date | DATE | Date the user signed up |
| events | event_id | INT | Unique event identifier |
| events | user_id | INT | User who performed the event |
| events | action_type | VARCHAR(10) | Event type such as A, B, or other actions |
| events | event_time | TIMESTAMP | Timestamp of the event |
| user_id | user_name | signup_date |
|---|---|---|
| 3 | Carla Diaz | 2024-01-03 |
| 1 | Alice Chen | 2024-01-01 |
| 8 | Hana Kim | 2024-01-08 |
| event_id | user_id | action_type | event_time |
|---|---|---|---|
| 101 | 1 | A | 2024-01-10 09:00:00 |
| 102 | 1 | B | 2024-01-10 20:00:00 |
| 103 | 1 | A | 2024-01-12 08:00:00 |
| 104 | 1 | B | 2024-01-13 09:00:00 |
| 105 | 2 | A | 2024-01-11 10:00:00 |
| 106 | 2 | C | 2024-01-11 11:00:00 |
| ... | ... | ... | ... |
| user_id | user_name | a_timestamp |
|---|---|---|
| 4 | Daniel Wu | 2024-01-09 23:30:00 |
| 2 | Brian Lee | 2024-01-11 10:00:00 |
| 1 | Alice Chen | 2024-01-12 08:00:00 |
| 6 | Fatima Noor | 2024-01-12 12:00:00 |
| 8 | Hana Kim | 2024-01-14 00:00:00 |
| Column | Type | Description |
|---|---|---|
| user_idPK | INT | Unique user identifier |
| user_name | VARCHAR(100) | User display name |
| signup_date | DATE | Date the user signed up |
| Column | Type | Description |
|---|---|---|
| event_idPK | INT | Unique event identifier |
| user_id | INT | User who performed the event |
| action_type | VARCHAR(10) | Event type such as A, B, or other actions |
| event_time | TIMESTAMP | Timestamp when the event occurred |
| user_id | user_name | signup_date |
|---|---|---|
| 3 | Carla Diaz | 2024-01-03 |
| 1 | Alice Chen | 2024-01-01 |
| 8 | Hana Kim | 2024-01-08 |
| 2 | Brian Lee | 2024-01-02 |
| 5 | Elena Rossi | |
| 4 | Daniel Wu | 2024-01-04 |
| 7 | Grace Park | 2024-01-07 |
| 6 | Fatima Noor | 2024-01-06 |
| 9 | Ivan Petrov | 2024-01-09 |
| 10 | Zane Miller | 2024-01-05 |
| 11 | Victor Gomez | 2024-01-05 |
| 12 | Zane Miller | 2024-01-12 |
| 13 | Yara Hassan | 2024-01-12 |
| 14 | Xavier Cole | null |
| 15 | Hana Kim | 2024-01-04 |
| 16 | Ben Carter | 2023-12-30 |
| 17 | Rosa Martinez | 2024-01-05 |
| 18 | Carla Diaz | 2024-01-07 |
| 19 | Carla Diaz | 2024-01-10 |
| 20 | Rosa Martinez | 2024-01-10 |
| 21 | Ivan Petrov | 2024-01-01 |
| 22 | Daniel Wu | 2024-01-08 |
| 23 | Olivia Reed | 2024-01-06 |
| 24 | Rosa Martinez | 2024-01-08 |
| 25 | Liam Brooks | 2024-01-08 |
| 26 | Ben Carter | 2024-01-07 |
| 27 | Alice Chen | 2024-01-05 |
| 28 | Priya Nair | 2024-01-04 |
| event_id | user_id | action_type | event_time |
|---|---|---|---|
| 101 | 1 | A | 2024-01-10 09:00:00 |
| 102 | 1 | B | 2024-01-10 20:00:00 |
| 103 | 1 | A | 2024-01-12 08:00:00 |
| 104 | 1 | B | 2024-01-13 09:00:00 |
| 105 | 2 | A | 2024-01-11 10:00:00 |
| 106 | 2 | C | 2024-01-11 11:00:00 |
| 107 | 3 | A | 2024-01-10 15:00:00 |
| 108 | 3 | B | 2024-01-11 14:59:00 |
| 109 | 4 | A | 2024-01-09 23:30:00 |
| 110 | 4 | B | 2024-01-11 00:00:01 |
| 111 | 5 | B | 2024-01-10 08:00:00 |
| 112 | 5 | A | 2024-01-10 09:00:00 |
| 113 | 5 | B | 2024-01-10 10:00:00 |
| 114 | 6 | A | 2024-01-12 12:00:00 |
| 115 | 6 | A | 2024-01-12 13:00:00 |
| 116 | 6 | B | 2024-01-13 11:00:00 |
| 117 | 7 | A | 2024-01-08 09:00:00 |
| 118 | 7 | B | 2024-01-09 09:00:00 |
| 119 | 8 | A | 2024-01-14 00:00:00 |
| 120 | 8 | B | |
| 121 | 9 | C | 2024-01-10 12:00:00 |
| 122 | A | 2024-01-15 10:00:00 | |
| 123 | 5 | cancel | 2024-01-18 09:40:46 |
| 124 | 3 | open | 2024-01-13 04:45:48 |
| 125 | 6 | purchase | 2024-01-16 12:36:06 |
| 126 | 2 | download | 2024-01-15 21:47:03 |
| 127 | 6 | cancel | 2024-01-17 10:45:20 |
| 128 | 7 | null | 2024-01-13 22:52:22 |
| 129 | 1 | approve | 2024-01-09 11:00:35 |
| 130 | 2 | logout | 2024-01-08 11:59:46 |
| user_id | user_name | a_timestamp |
|---|---|---|
| 4 | Daniel Wu | 2024-01-09 23:30:00 |
| 2 | Brian Lee | 2024-01-11 10:00:00 |
| 1 | Alice Chen | 2024-01-12 08:00:00 |
| 8 | Hana Kim | 2024-01-14 00:00:00 |