我是 Java 新手,正在从事一个项目。我正在尝试使用 Netbeans 从 MS Access 检索数据。在我重新安装操作系统之前一切正常。现在我运行代码时出现此错误。非常感谢您的帮助和建议
java.sql.SQLException: No data found
at sun.jdbc.odbc.JdbcOdbc.standardError(JdbcOdbc.java:7138)
at sun.jdbc.odbc.JdbcOdbc.SQLDriverConnect(JdbcOdbc.java:3073)
at sun.jdbc.odbc.JdbcOdbcConnection.initialize(JdbcOdbcConnection.java:323)
at sun.jdbc.odbc.JdbcOdbcDriver.connect(JdbcOdbcDriver.java:174)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at connect.ConnectDB(connect.java:24)
at StaffLogin.formWindowOpened(StaffLogin.java:125)
at StaffLogin.access$000(StaffLogin.java:13)
at StaffLogin$1.windowOpened(StaffLogin.java:47)
at java.awt.Window.processWindowEvent(Window.java:1859)
at javax.swing.JFrame.processWindowEvent(JFrame.java:279)
at java.awt.Window.processEvent(Window.java:1820)
at java.awt.Component.dispatchEventImpl(Component.java:4630)
at java.awt.Container.dispatchEventImpl(Container.java:2099)
at java.awt.Window.dispatchEventImpl(Window.java:2475)
at java.awt.Component.dispatchEvent(Component.java:4460)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
这是代码,我也省略了“生成的代码”和“外观”。如果需要这些,请告诉我。谢谢。
import java.sql.*;
import javax.swing.*;
public class StaffLogin extends javax.swing.JFrame {
Connection conn = null;
ResultSet rs = null;
PreparedStatement pst = null;
/**
* Creates new form StaffLogin
*/
public StaffLogin() {
initComponents();
}
private void formWindowOpened(java.awt.event.WindowEvent evt) {
// TODO add your handling code here:
conn = connect.ConnectDB();
}
private void cmdloginMouseClicked(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
conn = connect.ConnectDB();
String u = txtusername.getText();
String p = txtpassword.getText();
String sql = "SELECT * FROM Staff_Table WHERE Firstname='" + u+"' and Password='"+ p+"'";
try{
pst = conn.prepareStatement(sql);
rs = pst.executeQuery();
if (rs.next()){
JOptionPane.showMessageDialog(null,"Correct Password");
Interface i = new Interface();
i.setVisible(true);
}
else
JOptionPane.showMessageDialog(null,"Invalid Username or Password");
}
catch(Exception e){
JOptionPane.showMessageDialog(null, e);
}
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new StaffLogin().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton cmdlogin;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JPanel jPanel1;
private javax.swing.JPasswordField txtpassword;
private javax.swing.JTextField txtusername;
// End of variables declaration
最佳答案
这通常发生在您尝试多次读取列的值时。例如,这可能会抛出“找不到数据”:
ResultSet rs = statement.executeQuery(sql);
while (rs.next()) {
if ("value1".equals(rs.getString("mycolumn")) || "value2".equals(rs.getString("mycolumn"))) {
这样就可以正常工作了:
ResultSet rs = statement.executeQuery(sql);
while (rs.next()) {
String value = rs.getString("mycolumn");
if ("value1".equals(value) || "value2".equals(value)) {
关于java - 未找到数据 Java 异常,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/10197733/