我的结果集返回 0 条记录，但数据库具有该值，当在 mysql 中运行相同的 mysql

Question

在这里我从文本字段中获取值private void btnLoginActionPerformed(java.awt.event.ActionEvent evt) {                                             String userName = txtUserName.getText();    char[] passwordArray = txtPassword.getPassword();    String password = " ";    for(int i = 0; i < passwordArray.length; i++){        password = password + passwordArray[i];    }    int numberOfRecords = 0;    if(userName.equals("") || password.equals("")){        JOptionPane.showMessageDialog(this, "Please fill the form properly:");    }else{        System.out.println("i am here");        numberOfRecords = userServices.tryLogin(userName, password);        System.out.println("after number of records");        if(numberOfRecords == 1){            this.dispose();            mainForm.setVisible(true);        }else{            JOptionPane.showMessageDialog(this, "Sorry user name or password is incorrect:");        }    }    txtUserName.setText(" ");    txtPassword.setText("");}这是我的尝试登录方法public int tryLogin(String userName, String password) {    int numberOfRecords = 0;    SQLQueryUtil sql = new SQLQueryUtil();   sql.connect(false);   String query = "SELECT COUNT(*) AS `number_of_records` FROM `user` "            + "WHERE `userName`='" + userName + "' AND `password`='" + password + "';";    System.out.println(query);    ResultSet resultSet;    try{       resultSet = sql.executeQuery(query);        resultSet.isBeforeFirst();       numberOfRecords = resultSet.getRow();         System.out.println("number of Records =" + numberOfRecords);    } catch (Exception ex) {        ex.printStackTrace();    } finally{        sql.disconnect();    }    System.out.println("i am here also..............................");    return numberOfRecords;}当我点击登录按钮时，它显示以下结果驱动程序加载连接建立语句创建选择计数（*）number_of_records从user哪里userName=''和password=''；记录数 =0

Answer 1

您正在用空格声明密码。只需删除密码声明中的空格并尝试 .

String password = "";

for(int i = 0; i < passwordArray.length; i++){

    password = password + passwordArray[i];

}

Answer 2

getRow() 方法检索当前行号，而不是行数。因此，在开始迭代 ResultSet 之前，getRow() 返回 0。

所以尝试这种方式。

resultSet.last(); 

total = resultSet.getRow();

resultSet.beforeFirst();