Jdbc + Variable j

[Eric Habils]

Hi the Community,

I have a jframe with 3 textfields>
MatriculeToFind
MatriculeFinded
Name

The target is when I introduce id number in MatriculeTofind the program insert the id and the name into MatriculeFinded and nameFinded.

But in the program the result is null.

where is my error.

Thanks

Habiler

    private void MatriculeToFindMousePressed(java.awt.event.MouseEvent evt) {                                             
                Connection conn = null;
		PreparedStatement prepStmt = null;
                String MatriculeToFind = null;
 
		String SQL = "SELECT Matricule,Nom,Prenom FROM Signaletique WHERE Matricule = ?";
                        

		try {
			conn = Connect.ConnectDB();
			prepStmt = conn.prepareStatement(SQL);
                                      
                         prepStmt.setString(1, "MatriculeToFind".toString());   
                            
                            ResultSet rs = prepStmt.executeQuery(); {
                       
                        while( rs.next() ) {
                            MatriculeFinded.setText(rs.getString(1));
                            NomFinded.setText(rs.getString(2));
                            PrenomFinded.setText(rs.getString(3));
                            //Display values
                            
                                            }     
                                                                    }
            prepStmt.close();
                    } catch (SQLException e) {
            e.printStackTrace();
 
		}
    }                     

[Paul Clapham]

Eric Habils wrote:But in the program the result is null.

The result? I don't understand what you mean by "the result". It's a void method so it doesn't return any value, so clearly you must have something else in mind.

[Eric Habils]

The textFields MatriculeFinded and NameFinded are empty<  But when i replace the ? by a valid id number its ok

thanks

[Paul Clapham]

So that ? in the PreparedStatement is supposed to be some kind of number? In that case passing it the string "MatriculeToFind" is naturally going to result in the query returning zero rows, which is what is happening.

In other words, you have (at least) two problems: first, you don't have a way to tell the user that the ID number isn't in the table, which can happen when you pass the query an ID number which isn't there. And second, you aren't even passing an ID number to the query. I imagine that you thought that "MatriculeToFind".toString() would do something with the variable MatriculeToFind, but it doesn't. It is simply the string literal "MatriculeToFind" instead. And anyway using the MatriculeToFind variable would be pointless because it's null.

Perhaps you meant to get an ID number from somewhere and put it into that variable? If so you should really declare it as an int variable. And you do need some code which assigns it a value.

And why is that method given a MouseEvent as a parameter? It isn't used in the method, for one thing.

[Eric Habils]

I ve supressed the toString and replaced the ""String"" by int but no changes
Where do I filling the variable MatriculeToFind ?
Habiler

[Knute Snortum]

Eric Habils wrote:I ve supressed the toString and replaced the ""String"" by int but no changes
Where do I filling the variable MatriculeToFind ?
Habiler

I'm assuming that MatriculeToFind is a text field that contains the ID of the row you want to query.  I would need to see the rest of the program to be sure, but if you've declared MatriculeToFind outside of any method, constructor, or initializer block, then should be able to do something like this:

String idText = MatriculeToFind.getText();
// validate that idText is a positive int here
int id = Integer.parseInt(idText);

I haven't included the code to validate that MatriculeToFind is truly a positive integer.

[Eric Habils]

Now its give me an error at String idText = MatriculeToFind.getText();String

 private void MatriculeToFindMousePressed(java.awt.event.MouseEvent evt) {                                             
                Connection conn = null;
		PreparedStatement ps = null;
                String idText = MatriculeToFind.getText();
// validate that idText is a positive int here
                int id = Integer.parseInt(idText);

 
		String SQL = "SELECT Matricule,Nom,Prenom FROM Signaletique WHERE Matricule = ?";
                        

		try {
			conn = Connect.ConnectDB();
			ps = conn.prepareStatement(SQL);
                                      
                       
                            ResultSet rs =ps.executeQuery(); {
                        ps.setInt(1, id);   
                           System.out.println(id);   
                        while( rs.next() ) {
                                
                            MatriculeFinded.setText(rs.getString(1));
                            NomFinded.setText(rs.getString(2));
                            PrenomFinded.setText(rs.getString(3));
                            //Display values
                            }
                                            }     
                                                                    
           ps.close();
                    } catch (SQLException e) {
            e.printStackTrace();
 
		}
    }                 

[Knute Snortum]

1) What is the error?  Please post the full error text.
2) You're not showing the full program. We need the full program to see where MatriculeToFind is declared.

[Eric Habils]

My error is on line              rs.getString(1,MatriculeToFind);

/*
 /*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor0
 */
package database;

import java.awt.TextField;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 *
 * @author habiler
 */
public class NewJFrame extends javax.swing.JFrame {

    private static final long serialVersionUID = 1L;

    /**
     * Creates new form NewJFrame
     */
    public NewJFrame() {
        initComponents();
        Connection conn = Connect.ConnectDB();
    }
   
    /**
     * This method is called from within the constructor to initialize the form.
     * 25
     * +6
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        textField1 = new java.awt.TextField();
        jTextField1 = new javax.swing.JTextField();
        MatriculeToFind = new java.awt.TextField();
        MatriculeFinded = new java.awt.TextField();
        NomFinded = new java.awt.TextField();
        PrenomFinded = new java.awt.TextField();

        textField1.setText("textField1");

        jTextField1.setText("jTextField1");

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setFont(new java.awt.Font("Cambria", 1, 12)); // NOI18N

        MatriculeToFind.addMouseListener(new java.awt.event.MouseAdapter() {
            public void mousePressed(java.awt.event.MouseEvent evt) {
                MatriculeToFindMousePressed(evt);
            }
        });

        MatriculeFinded.setName("MatriculeFinded"); // NOI18N

        NomFinded.setName(""); // NOI18N

        PrenomFinded.setName(""); // NOI18N

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(52, 52, 52)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(MatriculeToFind, javax.swing.GroupLayout.PREFERRED_SIZE, 183, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(MatriculeFinded, javax.swing.GroupLayout.PREFERRED_SIZE, 88, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(19, 19, 19)
                        .addComponent(NomFinded, javax.swing.GroupLayout.PREFERRED_SIZE, 127, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(PrenomFinded, javax.swing.GroupLayout.PREFERRED_SIZE, 227, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addContainerGap(257, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(41, 41, 41)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(MatriculeToFind, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(54, 54, 54)
                        .addComponent(MatriculeFinded, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addComponent(NomFinded, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(PrenomFinded, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap(211, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

    private void MatriculeToFindMousePressed(java.awt.event.MouseEvent evt) {                                             
                Connection conn = null;
		PreparedStatement ps = null;
               
                // validate that idText is a positive int here
                
                 //String MatriculeToFind = null;
                
                String SQL = "SELECT Matricule,Nom,Prenom FROM Signaletique WHERE Matricule = ?";
                        

		try {
			conn = Connect.ConnectDB();
			ps = conn.prepareStatement(SQL);
                                      
                       
                        ResultSet rs = ps.executeQuery(); {
[u]                        rs.getString(1,MatriculeToFind);[/u][b][/b]
                        System.out.println("Matricule");   
                       if ( rs.next() ) {
                                
                            MatriculeFinded.setText(rs.getString(1));
                            NomFinded.setText(rs.getString(2));
                            PrenomFinded.setText(rs.getString(3));
                            //Display values
                            }
                                            }     
                                                                    
           ps.close();
                    } catch (SQLException e) {
            e.printStackTrace();
 
		}
    }                                            
    
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new NewJFrame().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private java.awt.TextField MatriculeFinded;
    private java.awt.TextField MatriculeToFind;
    private java.awt.TextField NomFinded;
    private java.awt.TextField PrenomFinded;
    private javax.swing.JTextField jTextField1;
    private java.awt.TextField textField1;
    // End of variables declaration                   
}

Error :

net.ucanaccess.jdbc.UcanaccessSQLException: UCAExc:::3.0.5 Parameter not set
	at net.ucanaccess.jdbc.UcanaccessPreparedStatement.executeQuery(UcanaccessPreparedStatement.java:241)
	at database.NewJFrame.MatriculeToFindMousePressed(NewJFrame.java:116)
	at database.NewJFrame.access$000(NewJFrame.java:18)
	at database.NewJFrame$1.mousePressed(NewJFrame.java:57)
	at java.awt.Component.processMouseEvent(Component.java:6530)
	at java.awt.Component.processEvent(Component.java:6298)
	at java.awt.TextComponent.processEvent(TextComponent.java:673)
	at java.awt.TextField.processEvent(TextField.java:588)
	at java.awt.Component.dispatchEventImpl(Component.java:4889)
	at java.awt.Component.dispatchEvent(Component.java:4711)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
	at java.awt.EventQueue.access$500(EventQueue.java:97)
	at java.awt.EventQueue$3.run(EventQueue.java:709)
	at java.awt.EventQueue$3.run(EventQueue.java:703)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
	at java.awt.EventQueue$4.run(EventQueue.java:731)
	at java.awt.EventQueue$4.run(EventQueue.java:729)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
Caused by: java.sql.SQLException: Parameter not set
	at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source)
	at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source)
	at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source)
	at org.hsqldb.jdbc.JDBCPreparedStatement.checkParametersSet(Unknown Source)
	at org.hsqldb.jdbc.JDBCPreparedStatement.fetchResult(Unknown Source)
	at org.hsqldb.jdbc.JDBCPreparedStatement.executeQuery(Unknown Source)
	at net.ucanaccess.jdbc.UcanaccessPreparedStatement.executeQuery(UcanaccessPreparedStatement.java:239)
	... 27 more
Caused by: org.hsqldb.HsqlException: Parameter not set
	at org.hsqldb.error.Error.error(Unknown Source)
	at org.hsqldb.error.Error.error(Unknown Source)
	... 32 more

[Jeanne Boyarsky]

It looks like you have these two commands sequentially:

ps = conn.prepareStatement(SQL);
ResultSet rs = ps.executeQuery();

You need this in between to actually replace the ? with a value:

ps.setString(1, "value");

You had this in all earlier post/iteration. Looks like it got lost in refactoring.

[Eric Habils]

Now I have a nullPointerException at line             ps.setString(1,"MatriculeToFind");

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor0
 */
package database;

import java.awt.TextField;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 *
 * @author habiler
 */
public class NewJFrame extends javax.swing.JFrame {

    private static final long serialVersionUID = 1L;

    /**
     * Creates new form NewJFrame
     */
    public NewJFrame() {
        initComponents();
        Connection conn = Connect.ConnectDB();
    }
   
    /**
     * This method is called from within the constructor to initialize the form.
     * 25
     * +6
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        textField1 = new java.awt.TextField();
        jTextField1 = new javax.swing.JTextField();
        MatriculeToFind = new java.awt.TextField();
        MatriculeFinded = new java.awt.TextField();
        NomFinded = new java.awt.TextField();
        PrenomFinded = new java.awt.TextField();

        textField1.setText("textField1");

        jTextField1.setText("jTextField1");

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setFont(new java.awt.Font("Cambria", 1, 12)); // NOI18N

        MatriculeToFind.addMouseListener(new java.awt.event.MouseAdapter() {
            public void mousePressed(java.awt.event.MouseEvent evt) {
                MatriculeToFindMousePressed(evt);
            }
        });

        MatriculeFinded.setName("MatriculeFinded"); // NOI18N

        NomFinded.setName(""); // NOI18N

        PrenomFinded.setName(""); // NOI18N

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(52, 52, 52)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(MatriculeToFind, javax.swing.GroupLayout.PREFERRED_SIZE, 183, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(MatriculeFinded, javax.swing.GroupLayout.PREFERRED_SIZE, 88, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(19, 19, 19)
                        .addComponent(NomFinded, javax.swing.GroupLayout.PREFERRED_SIZE, 127, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(PrenomFinded, javax.swing.GroupLayout.PREFERRED_SIZE, 227, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addContainerGap(257, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(41, 41, 41)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(MatriculeToFind, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(54, 54, 54)
                        .addComponent(MatriculeFinded, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addComponent(NomFinded, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(PrenomFinded, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap(211, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

    private void MatriculeToFindMousePressed(java.awt.event.MouseEvent evt) {                                             
                Connection conn = null;
		PreparedStatement ps = null;
               
                // validate that idText is a positive int here
                
                 String MatriculeToFind = null;
                
                String SQL = "SELECT Matricule,Nom,Prenom FROM Signaletique WHERE Matricule = ?";
                        
                 
		try {
                 ps = conn.prepareStatement(SQL);   
                                 
                    ps.setString(1,"MatriculeToFind");   
                    ResultSet rs = ps.executeQuery();
		                                
                      
                         
                       while ( rs.next() ) {
                             
                            System.out.println("Matricule"); 
                            System.out.println("id"); 
                            MatriculeFinded.setText(rs.getString(1));
                            NomFinded.setText(rs.getString(2));
                            PrenomFinded.setText(rs.getString(3));
                            //Display values
                            }
                                                 
                                                                    
           ps.close();
                    } catch (SQLException e) {
            e.printStackTrace();
 
		}
    }                                            
    
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new NewJFrame().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private java.awt.TextField MatriculeFinded;
    private java.awt.TextField MatriculeToFind;
    private java.awt.TextField NomFinded;
    private java.awt.TextField PrenomFinded;
    private javax.swing.JTextField jTextField1;
    private java.awt.TextField textField1;
    // End of variables declaration                   
}

[Jeanne Boyarsky]

You shouldn't be getting a null pointer there. You should be getting it on:

ps = conn.prepareStatement(SQL);   

I don't see anywhere you create the connection.

[Eric Habils]

at line 28 is the DB connected

[Jeanne Boyarsky]

Eric Habils wrote:at line 28 is the DB connected

Ah. This is line 28.

Connection conn = Connect.ConnectDB();

But on line 101, you have

Connection conn = null;

These are two different local variables that just happen to have the same name.

[Knute Snortum]

Are you sure this is what you want?
ps.setString(1,"MatriculeToFind");
Don't you want to get the text from the MatriculeToFind textfield, validate it, and convert it to an integer like we talked about?

[Eric Habils]

Hello to all,

I va suppressed

connection conn = null

and replaced

ps.setString(1,"MatriculeToFind");

by

ps.setString(1,MatriculeToFind.getText());

and it seems to run run.

Thanks for all

Habiler