CrudeUpsert.cs

static async Task Main(string[] args)
{
    using (var scope = new TransactionScope(TransactionScopeAsyncFlowOption.Enabled))
    {
	await Save(product);
	// we might update more entities 
	scope.Complete();
    }
}

public static async Task Save(Product product)
{
    using (var connection = new MySqlConnection(“...”))
    {
	await connection.OpenAsync();
	
	// select count(1) from Products where Id = @id
	if (await Exists(product, connection))
	    // update Products set ... where Id = @id
	    await Update(product, connection);
	else
	    // insert into Products values(...)
	    await Insert(product, connection);
    }
}