MySQL - Update table with row number per group

Question

Sample Data

id  |  order_id  |  instalment_num  | date_due
---------------------------------------------------------
1   |  10000     |  1               | 2010-07-09 00:00:00
2   |  10000     |  1               | 2010-09-06 11:39:56
3   |  10001     |  1               | 2014-04-25 15:46:52
4   |  10002     |  1               | 2010-01-11 00:00:00
5   |  10003     |  1               | 2010-01-04 00:00:00
6   |  10003     |  1               | 2016-05-31 00:00:00
7   |  10003     |  1               | 2010-01-08 00:00:00
8   |  10003     |  1               | 2010-01-06 09:06:26
9   |  10004     |  1               | 2010-01-11 11:25:07
10  |  10004     |  1               | 2010-01-12 07:06:42

Desired Result

id  |  order_id  |  instalment_num  | date_due
---------------------------------------------------------
1   |  10000     |  1               | 2010-07-09 00:00:00
2   |  10000     |  2               | 2010-09-06 11:39:56
3   |  10001     |  1               | 2014-04-25 15:46:52
4   |  10002     |  1               | 2010-01-11 00:00:00
5   |  10003     |  1               | 2010-01-04 00:00:00
8   |  10003     |  2               | 2010-01-06 09:06:26
7   |  10003     |  3               | 2010-01-08 00:00:00
6   |  10003     |  4               | 2016-05-31 00:00:00
9   |  10004     |  1               | 2010-01-11 11:25:07
10  |  10004     |  2               | 2010-01-12 07:06:42

As you can see, I have an instalment_num column which should show the number/index of each row belonging to the order_id, determined by the date_due ASC, id ASC order.

How can I update the instalment_num column like this?

Additional Notes

• The date_due column is not unique, and there may be many ids or order_ids with the exact same timestamp.

• If the timestamp is the same for two rows belonging to the same order_id, it should order them by id as a fallback.

• I require a query which will update this column.

Answer 1

This is how I would do it:

SELECT a.id,
    a.order_id,
    COUNT(b.id)+1 AS instalment_num,
    a.date_due
FROM sample_data a
    LEFT JOIN sample_data b ON a.order_id=b.order_id AND (a.date_due>b.date_due OR (a.date_due=b.date_due AND a.id>b.id))
GROUP BY a.id, a.order_id, a.date_due
ORDER BY a.order_id, a.date_due, a.id

UPDATE version attempt:

UPDATE sample_data
    LEFT JOIN (SELECT a.id,
    COUNT(b.id)+1 AS instalment_num
FROM sample_data a
    JOIN sample_data b ON a.order_id=b.order_id AND (a.date_due>b.date_due OR (a.date_due=b.date_due AND a.id>b.id))
GROUP BY a.id) c ON c.id=sample_data.id
SET sample_data.instalment_num=c.instalment_num

Answer 2

For the numbering to begin with 1:

UPDATE sample_data
    LEFT JOIN (SELECT a.id,
    COUNT(b.id) AS instalment_num
FROM sample_data a
    JOIN sample_data b ON a.order_id = b.order_id AND (a.date_due > b.date_due OR (a.date_due=b.date_due AND a.id + 1 > b.id))
GROUP BY a.id) c ON c.id = sample_data.id
SET sample_data.instalment_num = c.instalment_num