Comment # 2 on bug 1195369 from Fabian Vogt

> The 4*Qt5 SQL plugins have a `Provides: libqt5_sql_backend`. The solver picks the first one it finds.

Not necessarily: With a Suggests it's possible to tell the solver what the
"default" is.

I suggest to use boolean dependencies e.g. Requires: (qt6-sql-mysql or
qt6-sql-sqlite) for the backends which the application supports.