CODEWITHSUNDEEP
javasqlitejdbc
UsefulUserName
UsefulUserName

Reputation: 595

Converting resultSet to arrayList and printing it out

I am trying to convert a result set with 2 columns into an arraList of arrays. To check my code I then print it out. For that purpose I made a little table compromised of 2 columns á 5 rows.

Problem is that my test print prints out 5 times my original table. So now I'm confused. Is my way of converting the resultSet wrong or am I not printing right? Could somebody help?

Code:

public static void partner() {
    ArrayList <int[]> result = new ArrayList<int[]>();

    String select = "SELECT ID, age FROM individuen WHERE age BETWEEN 20 AND 40 " +
    "AND Familienstand IS 2 ORDER BY RANDOM() LIMIT 5";

    DBController dbc = DBController.getInstance();
    dbc.initDBConnection();


    try {
        Statement stmt = DBController.connection.createStatement();
        ResultSet rs = stmt.executeQuery(select);

        int columnCount = rs.getMetaData().getColumnCount();
        while(rs.next()){
            int[] row = new int[columnCount];
            for (int i = 0; i < columnCount ; i++){
                row[i] = rs.getInt(i + 1);
            }
            result.add(row);

        }
        Iterator<int[]> it = result.iterator();
        while (it.hasNext()) {
            for (int[] arr : result) {
                System.out.println(Arrays.toString(arr));
            }
                it.next();
        }
    } catch (SQLException e) {
        e.printStackTrace();
    }

}

Upvotes: 0

Views: 1115

Answers (2)

KhAn SaAb
KhAn SaAb

Reputation: 5366

keep only one loop either for or while loop.

   for (int[] arr : result) {
        System.out.println(Arrays.toString(arr));
    }

Upvotes: 3

Eran
Eran

Reputation: 393771

You have a nested iteration over your ArrayList, which means you iterate over the ArrayList multiple times (the number of times being the size() of the ArrayList).

You just need a single for loop :

    for (int[] arr : result) {
        System.out.println(Arrays.toString(arr));
    }

or a single while loop :

    Iterator<int[]> it = result.iterator();
    while (it.hasNext()) {
        System.out.println(Arrays.toString(it.next()));
    }

not both.

Upvotes: 1

Related Questions