can someone explain what this exactly does?

[liluma]

so i have writen a small program to create a new player (and also ask them from the database)

	public Speler registreerSpeler(String naam, SchipKlasse klasse,String schipNaam) 
	{
		{
			Speler speler = null;
			Statement statement;
			try
			{
				Connection connection = PersistentieController.getInstance().getConnection();
				statement = connection.createStatement();
				String naamCaptain = naam;
				String ship = schipNaam;
				
				String className = klasse.getNaamKlasse();
				int hitpoints = klasse.getHitpoints();
				int snelheid = klasse.getSpeedpoints();
				int cannons = klasse.getCannons();
				int rockets = klasse.getRockets();
				int AA = klasse.getAA();
				int soldiers = klasse.getSoldiers();
				int aircrafts = klasse.getAircrafts();
				int copters = klasse.getCopters();
				int mines = klasse.getMines();
				int schadepunten = 0;
				statement.executeUpdate("INSERT INTO SpelerShip (nameship,classname,hitpoints,speedpoints,cannons,rockets,AA,soldiers,aircrafts,copters,mines,schadepunten) VALUES ('" + ship + "', '" + className + "', '" + hitpoints + "', '" + snelheid + "', '" + cannons + "', '" + rockets + "', '" + AA + "', '" + soldiers + "', '" + aircrafts + "', '" + copters + "','" + mines + "','" + schadepunten + "')");
				statement.close();
				statement = connection.createStatement();
				statement.executeUpdate("INSERT INTO Spelers (naamcaptain,ship) VALUES ('" + naamCaptain + "','" + ship + "')");
				
				//statement.executeUpdate("INSERT INTO Spelers (Naam,Categorie) VALUES ('" + naam + "','" + categorieNaam + "')");
				statement.close();
				
			    String cmd = "select @@identity from ShipClass";
			    statement = connection.createStatement();
			    ResultSet rs = statement.executeQuery(cmd);
			    if (!rs.next())
			    	return null;
			    
			    speler = new Speler(naam, new Schip(klasse, schipNaam, schadepunten));
			    statement.close();
			} 
			catch ( SQLException sqlException )
			{
			    sqlException.printStackTrace();
			    PersistentieController.getInstance().closeConnection();
			} 
			  
			return speler;
		}

this is the code

now i'm only wondering what this does...

    String cmd = "select @@identity from ShipClass";
			    statement = connection.createStatement();
			    ResultSet rs = statement.executeQuery(cmd);
			    if (!rs.next())
			    	return null;

this is a picture of the relationship model of my database


i know it has to be there in order to work, but i just can't figure out what exactly happens...


tho i will learn this next year i would love to know what it does now.

please help me. :p ^^

grtz liluma

[camickr]

I don't know what that code is for.

I just wanted to suggest that you use a PreparedStatement for your SQL to make the code more readable and less error prone:

String sql = "INSERT INTO Page (Name, Title) VALUES (?, ?)";

PreparedStatement stmt = connection.prepareStatement(sql);

stmt.setString( 1, nameVariable );
stmt.setString( 2, titleVariable );
stmt.executeUpdate();

[liluma]

the program just writes information(strings, int) to a microsoft database...
that function makes a new record in two tables...

i know that preparedStatement are more clear and easier and less likely to make errors...
but i need to be able to do both...
so that's the only reason i used nrml statement here and manually put in the variables... :p

but i know it works correctly i'm just wondering what that last bit of code does...

    String cmd = "select @@identity from ShipClass";
			    statement = connection.createStatement();
			    ResultSet rs = statement.executeQuery(cmd);
			    if (!rs.next())
			    	return null;

[DarrylBurke]

Click here.

db

[liluma]

hmm that gave me the awnser indeed...

searched for awnser in the wrong place. :o :p

anyway ty for pointing me out in the right direction DarrylBurke. ^^