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使用for循環從數據庫檢索數據

[英]Data Retrieve from Database using for loop

 原文  2011-12-28 05:43:48  2   2    java/ mysql/ swing/ jtable

問題描述

我使用以下代碼從MYSQL數據庫中檢索數據。我為數據庫連接創建單獨的方法（GCotnStr），並在此代碼中調用該方法。數據庫連接和檢索數據工作正常。我的問題是我使用“ String StudName = TmpFlxTRs.getString（“StudName”）;“ 比如class，mark1，mark2，得到和設置Jtable中的值的結果。如何檢索數據並使用特定行在JTable中顯示，如何使用學生名稱檢索數據，如果我將參數作為“學生名稱”表示我沒有使用“String StudName = TmpFlxTRs.getString（”StudName“）獲得所有學生姓名;” 使用FOR LOOP。 

package designstudent;
import javax.swing.table.DefaultTableModel;
import java.sql.*;

public class FrmeA extends javax.swing.JFrame {

   Statement TmpFlxTSt=null;
      ResultSet TmpFlxTRs=null;
      GContnStr GCS=new GContnStr();

    public FrmeA() {
        initComponents();
    }

 public void initcon()
    {
 try{
     DefaultTableModel model=(DefaultTableModel)jTable1.getModel();
             GCS.GContnStr();
             TmpFlxTSt= GCS.GCotnStr.createStatement();
             String select = "Select * from studentmaster";
             TmpFlxTRs = TmpFlxTSt.executeQuery(select);

                int i = 0;
                while (TmpFlxTRs.next()){

                    String Name = TmpFlxTRs.getString("StudName");
                    String Class = TmpFlxTRs.getString("StudClass");
                    String Subj1 = TmpFlxTRs.getString("StudMrk1");
                    String Subj2= TmpFlxTRs.getString("StudMrk2");
                    String StudTot = TmpFlxTRs.getString("StudTot");
                    String StudRes= TmpFlxTRs.getString("StudRes");
                    String StudNo=TmpFlxTRs.getString("StudNo");
                    String StudId=TmpFlxTRs.getString("StudId");
                    model.addRow(new Object[]{Name,Class,Subj1,Subj2,StudTot,StudRes,StudId,StudNo});
}
        }
        catch (Exception e) {
                System.out.println(e);
            }
                }

    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        jPanel2 = new javax.swing.JPanel();
        CmdA = new javax.swing.JButton();
        CmdE = new javax.swing.JButton();
        CmdD = new javax.swing.JButton();
        cmdQ = new javax.swing.JButton();
        jPanel3 = new javax.swing.JPanel();
        jScrollPane1 = new javax.swing.JScrollPane();
        jTable1 = new javax.swing.JTable();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jPanel2.setBorder(javax.swing.BorderFactory.createTitledBorder(javax.swing.BorderFactory.createMatteBorder(1, 1, 1, 1, new java.awt.Color(0, 0, 255)), "Commands"));

        CmdA.setText("+");

        CmdE.setText("E");

        CmdD.setText("-");

        cmdQ.setText("Q");

        javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
        jPanel2.setLayout(jPanel2Layout);
        jPanel2Layout.setHorizontalGroup(
            jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel2Layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(CmdA, javax.swing.GroupLayout.PREFERRED_SIZE, 64, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(CmdE, javax.swing.GroupLayout.PREFERRED_SIZE, 71, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(CmdD, javax.swing.GroupLayout.DEFAULT_SIZE, 72, Short.MAX_VALUE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(cmdQ, javax.swing.GroupLayout.PREFERRED_SIZE, 72, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap())
        );
        jPanel2Layout.setVerticalGroup(
            jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel2Layout.createSequentialGroup()
                .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
                    .addGroup(javax.swing.GroupLayout.Alignment.LEADING, jPanel2Layout.createSequentialGroup()
                        .addGap(20, 20, 20)
                        .addComponent(CmdA, javax.swing.GroupLayout.PREFERRED_SIZE, 59, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGroup(javax.swing.GroupLayout.Alignment.LEADING, jPanel2Layout.createSequentialGroup()
                        .addGap(22, 22, 22)
                        .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(CmdD, javax.swing.GroupLayout.DEFAULT_SIZE, 57, Short.MAX_VALUE)
                            .addComponent(CmdE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                            .addComponent(cmdQ, javax.swing.GroupLayout.DEFAULT_SIZE, 57, Short.MAX_VALUE))))
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );

        jPanel3.setBorder(javax.swing.BorderFactory.createMatteBorder(1, 1, 1, 1, new java.awt.Color(0, 0, 255)));

        jTable1.setModel(new javax.swing.table.DefaultTableModel(
            new Object [][] {

            },
            new String [] {
                "StudName", "StudClass", "StudMrk1", "StudMrk2", "StudTot", "StudRes", "StudNO", "StudId"
            }
        ) {
            Class[] types = new Class [] {
                java.lang.String.class, java.lang.Integer.class, java.lang.Integer.class, java.lang.Integer.class, java.lang.Integer.class, java.lang.Integer.class, java.lang.Integer.class, java.lang.Integer.class
            };

            public Class getColumnClass(int columnIndex) {
                return types [columnIndex];
            }
        });
        jScrollPane1.setViewportView(jTable1);
        jTable1.getColumnModel().getColumn(0).setResizable(false);
        jTable1.getColumnModel().getColumn(0).setPreferredWidth(150);
        jTable1.getColumnModel().getColumn(1).setResizable(false);
        jTable1.getColumnModel().getColumn(1).setPreferredWidth(70);
        jTable1.getColumnModel().getColumn(2).setResizable(false);
        jTable1.getColumnModel().getColumn(2).setPreferredWidth(70);
        jTable1.getColumnModel().getColumn(3).setResizable(false);
        jTable1.getColumnModel().getColumn(3).setPreferredWidth(70);
        jTable1.getColumnModel().getColumn(4).setResizable(false);
        jTable1.getColumnModel().getColumn(4).setPreferredWidth(70);
        jTable1.getColumnModel().getColumn(5).setResizable(false);
        jTable1.getColumnModel().getColumn(5).setPreferredWidth(70);
        jTable1.getColumnModel().getColumn(6).setMinWidth(0);
        jTable1.getColumnModel().getColumn(6).setPreferredWidth(0);
        jTable1.getColumnModel().getColumn(6).setMaxWidth(0);
        jTable1.getColumnModel().getColumn(7).setMinWidth(0);
        jTable1.getColumnModel().getColumn(7).setPreferredWidth(0);
        jTable1.getColumnModel().getColumn(7).setMaxWidth(0);

        javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3);
        jPanel3.setLayout(jPanel3Layout);
        jPanel3Layout.setHorizontalGroup(
            jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 984, Short.MAX_VALUE)
            .addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel3Layout.createSequentialGroup()
                    .addContainerGap()
                    .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 964, Short.MAX_VALUE)
                    .addContainerGap()))
        );
        jPanel3Layout.setVerticalGroup(
            jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 249, Short.MAX_VALUE)
            .addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel3Layout.createSequentialGroup()
                    .addContainerGap()
                    .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 184, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addContainerGap(54, Short.MAX_VALUE)))
        );

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                .addContainerGap(657, Short.MAX_VALUE)
                .addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap())
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addContainerGap()
                    .addComponent(jPanel3, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addContainerGap()))
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGap(19, 19, 19)
                .addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(803, Short.MAX_VALUE))
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGap(190, 190, 190)
                    .addComponent(jPanel3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addContainerGap(492, Short.MAX_VALUE)))
        );

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 1016, Short.MAX_VALUE)
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(layout.createSequentialGroup()
                    .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 946, Short.MAX_VALUE)
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(layout.createSequentialGroup()
                    .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addContainerGap(13, Short.MAX_VALUE)))
        );

        pack();
        java.awt.Dimension screenSize = java.awt.Toolkit.getDefaultToolkit().getScreenSize();
        java.awt.Dimension dialogSize = getSize();
        setLocation((screenSize.width-dialogSize.width)/2,(screenSize.height-dialogSize.height)/2);
    }// </editor-fold>                        

    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                   FrmeA f= new FrmeA();
                 f.initcon();
                 f.setVisible(true);

            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton CmdA;
    private javax.swing.JButton CmdD;
    private javax.swing.JButton CmdE;
    private javax.swing.JButton cmdQ;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JPanel jPanel2;
    private javax.swing.JPanel jPanel3;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTable jTable1;
    // End of variables declaration                   

}

2 個解決方案

解決方案1
 1  2011-12-28 06:20:29

編寫自定義方法來修改您的查詢以獲取您想要的確切數據，例如，您希望獲得所有學生的姓名，您的查詢應該是String select = "Select StudName from studentmaster"而不是String select = "Select * from studentmaster"因此創建一個通用將獲取將由查詢提取的列的參數的方法

解決方案2
 1  2011-12-28 07:34:11

好吧，我不確定這是不是你的意思？ 

String select = "Select StudName  from studentmaster";
TmpFlxTRs = TmpFlxTSt.executeQuery(select);

    while (TmpFlxTRs.next()){                
       // TmpFlxTRs.getString(1) will have the corresponding name, add it to the table.
    }

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