Workaround SELECT ... ORDER BY (SELECT 1) related bug in Oracle's MySQL implementation, that can lead to completely wrong data being returned.

[lauxjpn]

The QuerySqlGenerator base implementation translates constant and parameter expressions in an OrderingExpression to (SELECT 1).

This leads to a bug in Oracle's MySQL, where completely wrong data is being returned under certain conditions.

As a workaround, we now just output 1 instead of (SELECT 1) for all database versions and types.

Fixes #1849

[ChrisJollyAU]

@lauxjpn Interesting. Had to do the exact same for Jet

[lauxjpn]

I am not yet completely convinced, that this PR fixes the issue completely for Pomelo. I will monitor our CI runs over the coming days to make sure, since the nature of the issue is a bit non-deterministic.

[lauxjpn]

This PR does not work as intended, but introduces a query bug. See #1849 (comment) for more information.
Reverted by #1870 for 9.0 and #1871 for 8.0.

/cc @ChrisJollyAU

[ChrisJollyAU]

@lauxjpn Actually Jet would not encounter the same problem. It doesn't support positional ORDER BY. Only normal column expressions. Had also forgotten that it had used just SELECT 1 all the way from its early days. My thoughts were actually on a modification I had to do for when it was within an WHERE NOT EXISTS clause (CirrusRedOrg/EntityFrameworkCore.Jet#202 )