string value not changing mysql c++

Hey everyone,
I been mucking around with mysql and ue4 yesterday and ive got my database connected etc, I have a register page at the moment, after I put in 1 lot of username and password combos I cannot change it again, it is changing through my blueprint that connects to it but not in the c++ side of things.

My .cpp

void UBP_Database_Connect::RegisterUser(FString un, FString pw)
#define dbHOST "tcp://"
#define dbUSER "root"
#define dbPASS ""
#define dbDB   "test"

	try {
		sql::Driver *driver;
		sql::Connection *con;
		sql::Statement *stmt;
		sql::ResultSet *res;
		sql::PreparedStatement *pstmt;

		static string UN(TCHAR_TO_UTF8(*un));
		static string PW(TCHAR_TO_UTF8(*pw));

		driver = get_driver_instance();
		con = driver->connect(dbHOST, dbUSER, dbPASS);

		stmt = con->createStatement();
		stmt->execute("USE " dbDB);
		res = stmt->executeQuery("SELECT (id) FROM test");
		int id = res->rowsCount() + 1;

		delete res;
		delete stmt;
		pstmt = con->prepareStatement("INSERT INTO test(id,username,password) VALUES (?,?,?)");
		pstmt->setInt(1, id);
		pstmt->setString(2, UN);
		pstmt->setString(3, PW);
		delete pstmt;
		delete con;

	catch (sql::SQLException)



my .h

	UFUNCTION(BlueprintCallable, Category = "DB")
	static FString RegisterUser(FString un, FString pw);

Any my bueprints

any help will be much appreciated :slight_smile: