Reputation: 537
I have a below dataset where I'm trying to get the min timestamp of the same values in a single column.
Here is my dataset.
I am trying to create a column to find user_first_comment for each interaction with dealer.
like below
is there any technique that i can use to add a incremental value for same values in columns. for example column RANK_Incremental,so that i can use Min wit hpartition to get final output.
Upvotes: 0
Views: 180
Reputation: 4694
With common table expressions (or derived tables) and window function support, try the following:
WITH step1 AS (
SELECT *, CASE WHEN LAG(note_type) OVER (PARTITION BY incident ORDER BY note_date) = note_type THEN 0 ELSE 1 END AS edge FROM incidents
)
, step2 AS (
SELECT *, SUM(edge) OVER (PARTITION BY incident ORDER BY note_date) AS grp FROM step1
)
SELECT *, FIRST_VALUE(note_date) OVER (PARTITION BY incident, grp ORDER BY note_date) AS first_date FROM step2
;
The result:
+----------+---------------------+----------------+------+------+---------------------+
| incident | note_date | note_type | edge | grp | first_date |
+----------+---------------------+----------------+------+------+---------------------+
| 5498091 | 2021-12-15 17:20:00 | USER_COMMENT | 1 | 1 | 2021-12-15 17:20:00 |
| 5498091 | 2021-12-15 17:21:00 | USER_COMMENT | 0 | 1 | 2021-12-15 17:20:00 |
| 5498091 | 2021-12-15 17:55:00 | DEALER_COMMENT | 1 | 2 | 2021-12-15 17:55:00 |
| 5498091 | 2021-12-15 17:59:00 | USER_COMMENT | 1 | 3 | 2021-12-15 17:59:00 |
| 5498091 | 2021-12-16 11:02:00 | USER_COMMENT | 0 | 3 | 2021-12-15 17:59:00 |
| 5498091 | 2021-12-16 16:46:00 | DEALER_COMMENT | 1 | 4 | 2021-12-16 16:46:00 |
+----------+---------------------+----------------+------+------+---------------------+
The setup:
CREATE TABLE incidents (
incident int
, note_date datetime
, note_type varchar(20)
)
;
INSERT INTO incidents VALUES
(5498091, '2021-12-15 17:20', 'USER_COMMENT')
, (5498091, '2021-12-15 17:21', 'USER_COMMENT')
, (5498091, '2021-12-15 17:55', 'DEALER_COMMENT')
, (5498091, '2021-12-15 17:59', 'USER_COMMENT')
, (5498091, '2021-12-16 11:02', 'USER_COMMENT')
, (5498091, '2021-12-16 16:46', 'DEALER_COMMENT')
;
Upvotes: 1