'upsert' syntax and real 'batch' syntax support

Now when I want to insert multiple records at once, I must use the saveAll method. And the saveAll method uses the save method↓

// in class `SimpleR2dbcRepository`
public <S extends T> Mono<S> save(S objectToSave) {

	Assert.notNull(objectToSave, "Object to save must not be null");

	if (this.entity.isNew(objectToSave)) {
		return this.entityOperations.insert(objectToSave);
	}

	return this.entityOperations.update(objectToSave);
}

it wiil check if each record is new.
I'd like to know if there is any support for 'upsert' syntax or real batch insert syntax (insert into ... values ​​(...), (...);)
Thanks in advance :)

Start with SimpleR2dbcRepository.save and saveAll, then trace the entity operations used for inserts and updates. Check whether the existing R2DBC APIs expose upsert or true multi-row insert behavior; done means the supported behavior and any required API scope are established for both requested forms.