java.sql.sqlexception列计数与第1行的值计数不匹配

Question

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         

    // TODO add your handling code here:
    try {  
        Class.forName("com.mysql.jdbc.Driver");  
        // establish connection  
        Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/grade", "root", "");  
        Statement statement = con.createStatement();  
        statement.executeUpdate("INSERT INTO marks(id,name,quiz,a1,a2,exam,marks,grade) VALUES ('" + id.getText() + "','" + name.getText() + "','" + quiz.getText() + "','"+a1.getText()+"','"+a2.getText()+"','"+"','"+exam.getText()+"','"+marks.getText()+"','"+grade.getText()+"')");  
        JOptionPane.showMessageDialog(null, "Record inserted...");  
        statement.close();  
        con.close();  

    } catch (SQLException | ClassNotFoundException e) {  
        JOptionPane.showMessageDialog(null, e);  
    }  
}                                        

Answer 1

您的错误消息表示您的Statement有问题。我建议改用PreparedStatement和局部变量，这些局部变量将允许您检查传递给[SQL] INSERT语句的值。

下面的代码只是我建议您使用的JDBC代码。请注意，不再需要使用Class.forName()加载JDBC驱动程序。我的代码还使用try-with-resources，这是关闭Connection和PreparedStatement之类的首选方式。

String sql = "INSERT INTO marks (id,"     +
                                "name,"   +
                                "quiz,"   +
                                "a1,"     +
                                "a2,"     +
                                "exam,"   +
                                "marks,"  +
                                "grade) " +
             "VALUES (?, ?, ?, ?, ?, ?, ?, ?)";
String theId = id.getText();
String theName = name.getText();
String theQuiz = quiz.getText();
String theA1 = a1.getText();
String theA2 = a2.getText();
String theExam = exam.getText();
String theMarks = marks.getText();
String theGrade = grade.getText();
try (Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/grade", "root", "");
     PreparedStatement statement = con.prepareStatement(sql)) {
    statement.setString(1, theId);
    statement.setString(2, theName);
    statement.setString(3, theQuiz);
    statement.setString(4, theA1);
    statement.setString(5, theA2);
    statement.setString(6, theExam);
    statement.setString(7, theMarks);
    statement.setString(8, theGrade);
    statement.executeUpdate();
}
catch (SQLException e) {
    e.printStackTrace();
}

由于您没有发布数据库表marks的结构，所以我不知道表列的数据类型，因此方法setString()可能不是最合适的。

您可以编辑您的问题并添加表格结构，我将相应地编辑我的答案。