Java/JDBC/Swing - Probleme beim Abrufen des nächsten Datensatzes

Question

Ich habe einige Probleme beim Abrufen des nächsten Datensatzes in meiner SQLite-Datenbank. Ich habe ausprobiert, um eine neue ArrayList und Instanz eines Mitarbeiters (eine Klasse mit Getters/Setter) jedoch habe ich noch Probleme. Ich habe die letzten eineinhalb Tage im Internet gesucht, um dieses Problem zu lösen. Ich habe versucht, mit if(rs.next)/while(rs.next) jedoch nur while scheint zu arbeiten. Ich habe Online geschaut und folgten mehrere Tutorials aber stoßen die Frage SQLITE TYPE_FORWARD_ONLY. ich umgesetzt haben:

ResultSet.TYPE_SCROLL_SENSITIVE, 
ResultSet.CONCUR_UPDATABLE 

Aber noch kein Glück, so entschied ich mich einen Iterator/Zähler als ID in meiner SQLite-Datenbank ist einzigartig hinzuzufügen. Das Problem scheint jedoch zu sein, dass der Iterator/Zähler nicht inkrementiert wird, wenn jedoch der Wert manuell gesetzt wird, d. H. 2, erhalte ich den zweiten Datensatz innerhalb der Datenbank und so weiter.

nextEmployee.addActionListener(new ActionListener() { 

     @Override 
     public void actionPerformed(ActionEvent e) { 

      // TODO Auto-generated method stub 
      Connection connection = null; 
      PreparedStatement pst = null; 
      Statement statement = null; 
      ResultSet rs = null; 
      int i = 1; 
      try {     
       Class.forName("org.sqlite.JDBC"); 
       connection = DriverManager.getConnection("jdbc:sqlite:employeeDatabase.sqlite"); 
       connection.setAutoCommit(false);       

       String sql = "SELECT ID, Name, Gender, DOB, Address, Postcode, NIN, JobTitle, StartDate, Salary, Email from employees WHERE ID= " +(i);          

       pst = connection.prepareStatement(sql); 
       rs = pst.executeQuery();  

       for (i = 1; i <= 4; i++){ 
        while (rs.next()){ 

         String id = rs.getString(1); 
         String name = rs.getString(2); 
         String gender = rs.getString(3); 
         String dob = rs.getString(4); 
         String Address = rs.getString(5); 
         String Postcode = rs.getString(6); 
         String NIN = rs.getString(7); 
         String JobTitle = rs.getString(8); 
         String StartDate = rs.getString(9); 
         String Salary = rs.getString(10); 
         String email = rs.getString(11); 

         idTextField.setText(id); 
         nameTextField.setText(name); 
         genderTextField.setText(gender); 
         dobTextField.setText(dob); 

         addressTextField.setText(Address); 
         postcodeTextField.setText(Postcode); 
         ninTextField.setText(NIN); 
         jobtitleTextField.setText(JobTitle); 
         startdateTextField.setText(StartDate); 
         salaryTextField.setText(Salary); 
         emailTextField.setText(email); 


         // i++; 
         connection.commit(); 

         JOptionPane.showMessageDialog(null, "Employee has been found"); 
        } 
       }     

       rs.close(); 
       pst.close(); 
       connection.close(); 
      } 


      catch (Exception e1) { 

       JOptionPane.showMessageDialog(null, "No more records exist"); 

      } 
     }}); 

Ich habe gerade keine Ideen mehr. Dies ist das letzte Puzzleteil, das ich erfolgreich erstellt/einfügen, löschen, suchen, aktualisieren implementiert habe. Kann mir jemand sagen, warum dieser Iterator/Zähler nicht erhöht wird?

Vielen Dank.

EDIT -

Mitarbeiter Klasse

public class Employee extends Person { 
    private int id; 
    private float salary; 
    private String startDate; 
    private String title; 
    private String email; 



    public int getid(){ 
     return id; 
    } 

    public void setid(int id){ 
     this.id = id; 
    } 

    public float getsalary(){ 
     return salary; 
    } 

    public void setsalary(float salary){ 
     this.salary = salary; 
    } 

    public String getstartDate(){ 
     return startDate; 
    } 

    public void setstartDate(String startDate){ 
     this.startDate = startDate; 
    } 

    public String gettitle(){ 
     return title; 
    } 

    public void settitle(String title){ 
     this.title = title; 
    } 

    public String getemail(){ 
     return email; 
    } 

    public void setemial(String email){ 
     this.email = email; 
    } 



    public Employee(){ 
     this("", 'N', "", new Date(), "", "", 0, 0, "", "", ""); 
    } 

    public Employee(String Name, char Sex, String natIncsNumber, Date date, String address, String postcode, int ID, float Salary, String Startdate, String Title, String Email) { 
     super(Name, Sex,natIncsNumber, date, address, postcode); 
     this.id = ID; 
     salary = 0.0f; 
     this.startDate = Startdate; 
     this.title = Title; 
     this.email = Email; 
    } 


    public void setSalary(float salry){ 
     salary = salry; 
    } 

    public String toString(){ 
     return "Employee ID = " + id+ ", Employee Salary = " + salary + " Start Date = " + startDate + 
       " Title = " + title + " Email = " + email + super.toString(); 
    } 


} 

Person Class-

import java.io.*; 
public class Person implements Serializable{ 

    protected String name; 
    protected char gender; 
    protected String natIncsNo; 
    protected Date dob; 
    protected String Address; 
    protected String Postcode; 

    public String getName(){ 
     return name; 
    } 

    public void setName(String name){ 
     this.name = name; 
    } 

    public char getGender(){ 
     return gender; 
    } 

    public void setGender(char gender){ 
     this.gender = gender; 
    } 

    public String getnatIncsNo(){ 
     return natIncsNo; 
    } 

    public void setnatIncsNo(String natIncsNo){ 
     this.natIncsNo = natIncsNo; 
    } 

    public Date getdob(){ 
     return dob; 
    } 

    public void setdob(Date dob){ 
     this.dob = dob; 
    } 

    public String getAddress(){ 
     return Address; 
    } 

    public void setAddress(String Address){ 
     this.Address = Address; 
    } 

    public String getPostcode(){ 
     return Postcode; 
    } 

    public void setPostcode(String Postcode){ 
     this.Postcode = Postcode; 
    } 


    public Person(String Name, char Sex, String natIncsNumber, Date date, String address, String postcode) { 
     name = Name; 
     gender = Sex; 
     natIncsNo = natIncsNumber; 
     dob = date; 
     Address = address; 
     Postcode = postcode; 
    } 


     public Person(){ 
      this("", 'N', "", new Date(), "", ""); 
     } 

    public String toString(){ 



     String output = " Name: " + name + " Gender: " + gender + " National Insurance Number: " + natIncsNo + 
       " Date Of Birth : " + dob + 
       " Address: " + Address + " Postcode: " + Postcode; 

     return output; 

    } 
    } 

EDIT X 2-

EmployeeDAO Klasse

import java.security.spec.ECFieldF2m; 
import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.PreparedStatement; 
import java.sql.ResultSet; 
import java.sql.SQLException; 
import java.sql.Statement; 
import java.util.ArrayList; 

import javax.swing.JLabel; 
import javax.swing.JOptionPane; 

public class EmployeeDAO extends Employee { 

    private Connection con; 
    private Statement st; 
    private ResultSet rs; 

    public EmployeeDAO() { 



     Connection connection = null; 
     try { 
      Class.forName("org.sqlite.JDBC"); 
      connection = DriverManager.getConnection("jdbc:sqlite:employeeDatabase.sqlite"); 
     } catch (Exception e) { 
      System.err.println(e.getClass().getName() + ": " + e.getMessage()); 
      System.exit(0); 
     } 
     System.out.println("Connection - database driver found"); 




     //insertEmployeeAtID(); 
     //selectAllEmployees(); 
     //insertEmployee(); 
     //deleteEmployeeByID(); 
    } 





    public Statement getConnection() { 
     return st; 
    } 

    public void closeConnection() throws SQLException { 
     if (con != null) con.close(); 
    } 



    public ArrayList<Employee> selectAllEmployees(){ 
     Connection connection = null; 
     Statement statement = null; 
     try { 
      Class.forName("org.sqlite.JDBC"); 
      connection = DriverManager.getConnection("jdbc:sqlite:employeeDatabase.sqlite"); 
      connection.setAutoCommit(false); 
      System.out.println("Read operation - database successfully opened"); 

      statement = connection.createStatement(); 
      ResultSet resultset = statement.executeQuery("SELECT * from employees"); 
      while (resultset.next()) { 
       int id = resultset.getInt("id"); 
       String name = resultset.getString("name"); 
       String email = resultset.getString("email"); 
       String gender = resultset.getString("gender"); 
       String dob = resultset.getString("dob"); 
       String Address = resultset.getString("address"); 
       String Postcode = resultset.getString("Postcode"); 
       String NIN = resultset.getString("NIN"); 
       String JobTitle = resultset.getString("JobTitle"); 
       String StartDate = resultset.getString("StartDate"); 
       String Salary = resultset.getString("Salary"); 


       System.out.println("ID : " + id); 
       System.out.println("Name : " + name); 
       System.out.println("Gender : " + gender); 
       System.out.println("Date Of Birth : " + dob); 
       System.out.println("Address : " + Address); 
       System.out.println("Postcode : " + Postcode); 
       System.out.println("National Insurance Number : " + NIN); 
       System.out.println("Job Title : " + JobTitle); 
       System.out.println("Start Date : " + StartDate); 
       System.out.println("Salary : " + Salary); 
       System.out.println("Email: " + email); 
       System.out.println(); 
      } 
      resultset.close(); 
      statement.close(); 
      connection.close(); 
     } catch (Exception e) { 
      System.err.println(e.getClass().getName() + ": " + e.getMessage()); 
      System.exit(0); 
     } 
     System.out.println("Read operation successfully done"); 
     return new ArrayList<Employee>(); 

    } 


    public String selectEmployeeByName() { 
     Connection connection = null; 
     Statement statement = null; 
     try { 
      Class.forName("org.sqlite.JDBC"); 
      connection = DriverManager.getConnection("jdbc:sqlite:employeeDatabase.sqlite"); 
      connection.setAutoCommit(false); 
      System.out.println("Read operation - database successfully opened"); 

      statement = connection.createStatement(); 
      ResultSet resultset = statement.executeQuery("SELECT * from employees WHERE Name = 'Brad Stones';"); 
      while (resultset.next()) { 
       int id = resultset.getInt("id"); 
       String name = resultset.getString("name"); 
       String email = resultset.getString("email"); 
       String gender = resultset.getString("gender"); 
       String dob = resultset.getString("dob"); 
       String Address = resultset.getString("address"); 
       String Postcode = resultset.getString("Postcode"); 
       String NIN = resultset.getString("NIN"); 
       String JobTitle = resultset.getString("JobTitle"); 
       String StartDate = resultset.getString("StartDate"); 
       String Salary = resultset.getString("Salary"); 

       /* 
       System.out.println("ID : " + id); 
       System.out.println("Name : " + name); 
       System.out.println("Gender : " + gender); 
       System.out.println("Date Of Birth : " + dob); 
       System.out.println("Address : " + Address); 
       System.out.println("Postcode : " + Postcode); 
       System.out.println("National Insurance Number : " + NIN); 
       System.out.println("Job Title : " + JobTitle); 
       System.out.println("Start Date : " + StartDate); 
       System.out.println("Salary : " + Salary); 
       System.out.println("Email: " + email); 
       System.out.println(); 
       */ 
      } 
      resultset.close(); 
      statement.close(); 
      connection.close(); 
     } catch (Exception e) { 
      System.err.println(e.getClass().getName() + ": " + e.getMessage()); 
      System.exit(0); 
     } 
     System.out.println("Read operation successfully done"); 
      return toString(); 
    } 


    public boolean insertEmployee(){ 

     Connection connection = null; 
     Statement statement = null; 
     try { 
      Class.forName("org.sqlite.JDBC"); 
      connection = DriverManager.getConnection("jdbc:sqlite:employeeDatabase.sqlite"); 
      connection.setAutoCommit(false); 
      System.out.println("Insert operation -database successfully opened"); 
      statement = connection.createStatement(); 
      String sql = "INSERT INTO employees (id, name, gender, NIN, dob, Address, Postcode,startDate, salary, email, JobTitle) " 
        + "VALUES ('1', 'Brad Stones', 'M', 'YU6593864T', '09-01-1987', '100 Dalton Road', 'M1 7TA', '09-01-1981','25000', 'BradSmith@mail.com', 'Tutor')"; 


      statement.executeUpdate(sql); 
      statement.close(); 
      connection.commit(); 
      connection.close(); 
     } catch (Exception e) { 
      System.err.println(e.getClass().getName() + ": " + e.getMessage()); 
      System.exit(0); 
     } 
     System.out.println("Records successfully created"); 
     return false; 
    } 




    public boolean insertEmployeeAtID(){ 

     Connection connection = null; 
     Statement statement = null; 
     try { 
      Class.forName("org.sqlite.JDBC"); 
      connection = DriverManager.getConnection("jdbc:sqlite:employeeDatabase.sqlite"); 
      connection.setAutoCommit(false); 
      System.out.println("Update operation - database successfully opened"); 

      statement = connection.createStatement(); 
      String sql = "UPDATE employees set JobTitle = 'Potato' where ID=1;"; 
      statement.executeUpdate(sql); 
      connection.commit(); 
      statement.close(); 
      connection.close(); 
     } catch (Exception e) { 
      System.err.println(e.getClass().getName() + ": " + e.getMessage()); 
      System.exit(0); 
     } 
     System.out.println("Update operation successfully done"); 
     return false; 
     } 




    public boolean deleteEmployeeByID(){ 

     Connection connection = null; 
      Statement statement = null; 
      try { 
       Class.forName("org.sqlite.JDBC"); 
       connection = DriverManager.getConnection("jdbc:sqlite:employeeDatabase.sqlite"); 
       connection.setAutoCommit(false); 
       System.out.println("Delete operation -database successfully opened"); 
       statement = connection.createStatement(); 
       String sql = "DELETE from employees where ID= 1"; 
       statement.executeUpdate(sql); 
       connection.commit(); 
       statement.close(); 
       connection.close(); 
      } catch (Exception e) { 
       System.err.println(e.getClass().getName() + ": " + e.getMessage()); 
       System.exit(0); 
      } 
      System.out.println("Delete operation successfully done"); 
     return false; 
    } 

} 

nextEmployee Method-

List<Employee> list= empDAO.selectAllEmployees(); 

     int counter=0; 
     nextEmployee.addActionListener(new ActionListener() { 
      boolean isfirstTime = true; 


      @Override 
      public void actionPerformed(ActionEvent e) { 
       if (isfirstTime) { 
        Connection connection = null; 
        PreparedStatement pst = null; 
        Statement statement = null; 
        ResultSet rs = null; 
        int i = 1; 
        try { 

         Class.forName("org.sqlite.JDBC"); 
         connection = DriverManager.getConnection("jdbc:sqlite:employeeDatabase.sqlite"); 
         connection.setAutoCommit(false); 

         String sql = "SELECT ID, Name, Gender, DOB, Address, Postcode, NIN, JobTitle, StartDate, Salary, Email from employees WHERE ID= " 
           + (i); 

         pst = connection.prepareStatement(sql); 
         rs = pst.executeQuery(); 

         while(rs.next()){ 
          EmployeeDAO empDao=new EmployeeDAO(); 
          //set the variables for the employee 


          String id = rs.getString(1); 
          String name = rs.getString(2); 
          String gender = rs.getString(3); 
          String dob = rs.getString(4); 
          String Address = rs.getString(5); 
          String Postcode = rs.getString(6); 
          String NIN = rs.getString(7); 
          String JobTitle = rs.getString(8); 
          String StartDate = rs.getString(9); 
          String Salary = rs.getString(10); 
          String email = rs.getString(11); 

          idTextField.setText(id); 
          nameTextField.setText(name); 
          genderTextField.setText(gender); 
          dobTextField.setText(dob); 

          addressTextField.setText(Address); 
          postcodeTextField.setText(Postcode); 
          ninTextField.setText(NIN); 
          jobtitleTextField.setText(JobTitle); 
          startdateTextField.setText(StartDate); 
          salaryTextField.setText(Salary); 
          emailTextField.setText(email); 

          list.add(empDao); 


         } 


         rs.close(); 
         pst.close(); 
         connection.close(); 
        } 

        catch (Exception e1) { 

         JOptionPane.showMessageDialog(null, "No more records exist"); 

        } 
       }else{ 
        Employee emp=list.get(counter); 
        idTextField.setText(String.valueOf(emp.getid())); 
        //and so on. always get from emp 
        JOptionPane.showMessageDialog(null, "Employee has been found"); 


       } 
      } 
     }); 

Answer 1

mit dem Code, den Sie für mich, krank Post Sie einige von mir Code ist zu viel geschrieben, wo ich eine dao-Klasse erstellt und wie kann ich es verwenden.

dao Klasse:

public class SchnitzelDBDAO { 

private static final Logger LOG = LoggerFactory.getLogger(SchnitzelDBDAO.class); 
private Properties dbProperties; 
private String action = ""; 
private Vector<Gericht> mealsActionPerformedOn; 

public SchnitzelDBDAO() { 
    dbProperties = new Properties(); 
    String stage = System.getProperty("stage", "prod"); 
    LOG.info("Loading stage properties: {} ", stage); 
    String file = stage + ".settings.txt"; 
    try (InputStream in = this.getClass().getClassLoader().getResourceAsStream(file)) { 
     dbProperties.load(in); 
    } catch (Exception e) { 
     LOG.error("Properties konnten nicht geladen werden: ", e); 
     throw new RuntimeException(e); 
    } 
    mealsActionPerformedOn=new Vector<Gericht>(); 
} 

private Connection createConnection() throws Exception { 
    return DriverManager.getConnection(dbProperties.getProperty("server"), dbProperties); 
} 

public Vector<Gericht> findGericht(java.util.Date von, java.util.Date bis) throws Exception { 
    Vector<Gericht> v = new Vector<Gericht>(); 
    java.sql.Date[] dates = testDate(von, bis); 
    try (Connection connect = createConnection()) { 
     LOG.info("Searching for meals"); 
     String query = "select * from Gericht where date BETWEEN ? and ? order by date asc"; 
     PreparedStatement statement = connect.prepareStatement(query); 

     statement.setDate(1, dates[0]); 
     statement.setDate(2, dates[1]); 
     ResultSet rs = statement.executeQuery(); 
     while (rs.next()) { 
      Gericht g = new Gericht(); 
      g.setId(rs.getInt("id")); 
      String str = rs.getString("classification"); 
      g.setClassification(Classification.valueOf(str)); 
      g.setDate(rs.getDate("date")); 
      g.setName(rs.getString("name")); 
      g.setPreisExtern(rs.getBigDecimal("preisExtern")); 
      g.setPreisIntern(rs.getBigDecimal("preisIntern")); 
      v.add(g); 
     } 

     return v; 
    } 
} 
} 

dann es so in einem gewissen Klasse nennen. Die erste Zeile ist eine Membervariable in dieser Klasse.

SchnitzelDBDAO dbConnector = new SchnitzelDBDAO(); 
dbConnector.remove(gerichte.get(table.getSelectedRow()).getDate()); 

ich hoffe, dass Sie irgendwie Ihren Code Mine anpassen können und erhalten Sie Ihren Code richtig Versuchen