[3.x] Use row_number window function on MySQL and MariaDB if supported

[richard67]

Pull Request for Issue #290 .

Alternative to PRs #291 and #300 .

See also joomla/joomla-cms#42333 .

Summary of Changes

Use the ROW_NUMBER() window function in the selectRowNumber method on MySQL >= 8.0.0 and MariaDB >= 10.2.0.

Different to PR #300 , this one here extends the database driver and database interface by the new method hasRowNumberSupport to tell if the database engine supports the ROW_NUMBER() window function, and the MysqlQueryBuilder uses that method. The new method might be used by 3rd party extensions of the CMS, too.

The MySQL drivers set a new property rownum when connecting to the database, and the new hasRowNumberSupport method just returns the value of that property, so the checks for MariaDB and the version are not done with every call to the selectRowNumber query method like it is done in PR #300 , so it should be a bit faster.

Also different to PR #300 , this one here uses the ROW_NUMBER() window function whenever supported, i.e. as said with MySQL >= 8.0.0 and MariaDB >= 10.2.0. The other PR #300 does that only for MariaDB >= 11.0.0 in order to play safe and because issues where only reported for MariaDB 11, but I think that's not really necessary. Using the ROW_NUMBER() is more reliable than the "hack" with the SQL variable (@rownum).

I could not find any unit tests for the selectRowNumber method, so no changes on unit tests with this PR.

Testing Instructions

See joomla/joomla-cms#42333 .

Documentation Changes Required

None.

[richard67]

Closing in favour of PR #300 .