onConflictDoNothing method
Prepares SQLite/PostgreSQL duplicate-key suppression for this insert.
An explicit target must match a declared primary or unique key. Omitting
it uses the database's untargeted ON CONFLICT DO NOTHING behavior.
Implementation
Mutation<F> onConflictDoNothing({
List<ReadField<Object?>> Function(F)? target,
}) =>
_withConflict(target == null ? [] : target(queryFields), const [], null);