我有一个c程序，它试图将数据插入mysql数据库。数据可能已经在数据库中，在这种情况下，它只是覆盖它。例子：

MySqlConection dbConnection = ...; // Setup connection
int numCustomersToUpdate = 3;

String query =
    "INSERT INTO customer_regions (customer_id, region_id)
    VALUES (1, 205), (2, 314), (3, 151) // 3 customers
    ON DUPLICATE KEY UPDATE region_id = VALUES(region_id)";

MySqlCommand cmd = new MySqlCommand(query, dbConnection);

int rowsAffected = cmd.ExecuteNonQuery();
if (rowsAffected == numCustomersToUpdate)
{
    // Data either did not exist before and was inserted,
    // or already existed and overwritten
}
else
{
    // Error inserting data
}

问题是如果数据被覆盖， rowsAffected 为0，这被视为错误。不管数据是被插入还是被覆盖，我怎么能认为它是一个成功的sql执行呢？