Sort by rating and another column is inconsistent when a value is rated and then unrated

Steps to reproduce

1. Create a table with at least two columns; one of them is a rating column, the other is some other sortable field
2. Add a few items in the table. Rate one of the items, and then clear the rating. In the db (oc_tables_row_cells_number), this is now a value of 0. Make sure that some of the items are not rated
3. Sort the ratings in descending order, then sort another column.

Let's give a simple example

number	rating
2	5
3	0 (previously rated)
1	unrated (null)

Sort by rating DESC, then NUMBER ASC

Expected behavior

The item that was rated and then unrated is treated equivalently to an item that is unrated. Secondary sort takes over

number	rating
2	5
1	unrated (null)
3	0 (previously rated)

Actual behavior

The item that was rated and then unrated is treated above null

number	rating
2	5
3	0 (previously rated)
1	unrated (null)

Attached, see a snippet of a real example I observed. Column 1 is a number, column 2 is a rating column. Sort is by priority (column 2), then duration. Fields that are 0 were rated then unrated.

26-09-03_04-44_Pending items.csv

Tables app version

2.3.0

Browser

Firefox 1.54.1

Client operating system

Linux

Operating system

Linux (Docker)

Web server

Apache

PHP engine version

Other

Database

PostgreSQL

Additional info

PHP 8.5.10. Image https://hub.docker.com/_/nextcloud.

Reproduce the issue in the Tables app using PostgreSQL with a rating value that is cleared and becomes 0, alongside an unrated null value. Start by tracing the table sorting behavior for rating DESC followed by the secondary column; done means previously rated and never-rated rows are treated equivalently so the secondary sort determines their order.