Assuming I have the following table:
| id | category_id | item_id | created_at |
|---|---|---|---|
| 7 | 11 | 106 | 2024-05-06 |
| 6 | 3 | 102 | 2024-05-06 |
| 5 | 11 | 101 | 2024-05-05 |
| 4 | 9 | 98 | 2024-05-04 |
| 3 | 3 | 97 | 2024-05-03 |
| 2 | 1 | 91 | 2024-05-02 |
| 1 | 11 | 89 | 2024-05-01 |
How can I select all the rows, and add a column that represents the order of the creation for each item grouped by its category?
The result should be:
| id | category_id | item_id | item_order_by_category | created_at |
|---|---|---|---|---|
| 7 | 11 | 106 | 3 | 2024-05-06 |
| 6 | 3 | 102 | 2 | 2024-05-06 |
| 5 | 11 | 101 | 2 | 2024-05-05 |
| 4 | 9 | 98 | 1 | 2024-05-04 |
| 3 | 3 | 97 | 1 | 2024-05-03 |
| 2 | 1 | 91 | 1 | 2024-05-02 |
| 1 | 11 | 89 | 1 | 2024-05-01 |
It can either be by the order of the id column or the created_at column
Is it doable with a query with good performance? Or I will need to add some more information like a relationship table for that?
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