Question

我必须将ms访问数据库中的数据显示到标签。表包含这些列名称

ID(Long Integer), 
Name(Text),)
Gender(Text),
Address(Text), 
City (Text).

用户选择组合框值，这些值是来自表的ID，并且相应地显示相应的数据。错误是：

sucess sssssucess

java.sql.SQLException: [Microsoft][ODBC Microsoft Access Driver] Data type mismatch in criteria expression.

  package studentdetails;

  import javax.swing.*;
  import java.awt.*;
  import java.awt.event.*;
  import java.util.*;
  import java.sql.*;
  import java.awt.event.KeyAdapter.*;
  import java.awt.event.ActionListener.*;
  import javax.swing.AbstractButton.*;
  import java.text.SimpleDateFormat;
  import java.util.logging.Level;
  import java.util.logging.Logger;

 class StudentDetails extends JFrame implements ActionListener,KeyListener
  {
   JLabel l1,l2,l3,l4,l5,l6,l7,l8,l9;
   JLabel ll1,ll2,ll3,ll4,ll5,ll6,ll7;
   JButton b1,b2,b3;
   JComboBox c1;
   Connection conn;


public StudentDetails()
{
    super("Institute Management System");

    l1=new JLabel("ID::");
    l2=new JLabel("STUDENT NAME::");
    l3=new JLabel("GENDER::");
    l4=new JLabel("ADDRESS::");
    l5=new JLabel("CITY::");
    l6=new JLabel("CONTACT NO.::");
    //l7=new JLabel("DATE OF JOINING::");
    l8=new JLabel("STUDENT DETAILS::");
    l9=new JLabel("SELECT THE STUDENT ID:");

    ll1  = new JLabel();
            ll2  = new JLabel();
            ll3  = new JLabel();
            ll4  = new JLabel();
            ll5  = new JLabel();
            ll6  = new JLabel();
            //ll7  = new JLabel();



    b1=new JButton("VIEW");
    b2=new JButton("BACK");
    b3=new JButton("CLEAR");


    c1=new JComboBox();


    add(l8);
    l8.setBounds(210,30,150,80);

    add(l9);
    l9.setBounds(55,75,150,80);

    add(c1);
    c1.setBounds(250,100,150,30);

    add(l1);
    l1.setBounds(120,150,150,30);
    add(ll1);
    ll1.setBounds(250,150,150,30);

    add(l2);
    l2.setBounds(120,200,150,30);
    add(ll2);
    ll2.setBounds(250,200,150,30);

    add(l3);
    l3.setBounds(120,250,150,30);
    add(ll3);
    ll3.setBounds(250,250,150,30);

    add(l4);
    l4.setBounds(120,300,150,30);
    add(ll4);
    ll4.setBounds(250,300,150,30);

    add(l5);
    l5.setBounds(120,350,150,30);
    add(ll5);
    ll5.setBounds(250,350,150,30);

    /*add(l6);
    l6.setBounds(120,400,150,30);
    add(ll6);
    ll6.setBounds(250,400,150,30);

    add(l7);
    l7.setBounds(120,450,150,30);
    add(ll7);
    ll7.setBounds(250,450,150,30);
    */

    add(b1);
    b1.setBounds(500,100,80,30);
    add(b2);
    b2.setBounds(200,520,80,30);
    add(b3);
    b3.setBounds(450,520,80,30);



    setSize(700,700);
    setBackground(Color.BLUE);
    setLayout(null);
    setVisible(true);
    setExtendedState(MAXIMIZED_BOTH);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    b1.addActionListener(this);
    b2.addActionListener(this);
    b3.addActionListener(this);

            try
            {
                Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
                conn=DriverManager.getConnection("jdbc:odbc:LANGUAGEDSN");
                System.out.println("sucess");
                Statement stmt=conn.createStatement();
                String str = "Select ID from STUDENTDETAILS";
                ResultSet rs = stmt.executeQuery(str);
                while(rs.next())
                {
                     c1.addItem(rs.getString(1));
                }
            } 
            catch(Exception e)
            {
                System.out.println(e);
    }

}



public void actionPerformed(ActionEvent ae)
{
        Object ob=ae.getSource();

        String i = (String)c1.getSelectedItem();
        //SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd  HH:mm", Locale.getDefault());
        //String sdt_ = sdf.format(dt_);

        if(ob==b1)
        {

            try
    {
                Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
                conn=DriverManager.getConnection("jdbc:odbc:LANGUAGEDSN");
                Statement stmt=conn.createStatement();

                String st = "Select * from STUDENTDETAILS where ID ='"+i+"'";
                System.out.println("sssssucess");
                ResultSet rs = stmt.executeQuery(st);
                while(rs.next())
                {


                   l1.setText(rs.getString(1));

                    ll2.setText(rs.getString(2));
                    ll3.setText(rs.getString(3));
                    ll4.setText(rs.getString(4));
                    ll5.setText(rs.getString(5));


                }
            }
            catch(Exception e)
            {
                    System.out.println(e);
            }
        }

        else if(ob==b2)
        {
            ll1.setText("");
            ll2.setText("");
            ll3.setText("");
            ll4.setText("");
            ll5.setText("");
            //ll6.setText("");
            //ll7.setText("");
        }
    }





public static void main(String args[])
{
    new StudentDetails();
}

@Override
public void keyTyped(KeyEvent e) {
    throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}

@Override
public void keyPressed(KeyEvent e) {
    throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}

@Override
public void keyReleased(KeyEvent e) {
    throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}

Answer 1

首先，使用PreparedStatements

第二个...在引号中包含您的id值，'+i+'将使Access（以及几乎所有数据库）将值视为String，我怀疑它是什么。尝试删除引号

String st = "Select * from STUDENTDETAILS where ID =" + i;

第三......像素完美布局是现代UI开发中的一种幻觉。您无法控制不同平台的渲染管道。这将使你的像素完美，并变成乱码。

Swing旨在与布局管理器配合使用，这些功能使您能够专注于工作流程，而不是处理每种可能的DPI，字体大小和其他渲染问题的组合。

花点时间学习和使用合适的布局管理器，并查看Laying Out Components Within a Container了解更多详情

从java中的ms访问获取数据

1 个答案: