小编Mik*_*ike的帖子

下面的snipets来自我的Form1代码.因为我的MessageBox.Show(...),我一直得到格式异常; 我的Stop()方法中的声明.为什么？我究竟做错了什么？...

    private TimeSpan iterationDuration = TimeSpan.Zero;
    ...

    public void Stop()
    {
        IsGameOver = true;
        MessageBox.Show(String.Format("Game Over\n\nScore = {0}\n\n Time Duration =   {l}", score, iterationDuration));
        Application.Exit();
    }


    public void Start()
    {

        score = 0;
        IsGameOver = false;

        currentRedLightX = 0;
        currentRedLightY = 0;

        currentGreenLightX = width / 2;
        currentGreenLightY = height / 2;


        double minIterationDuration = SPEED; // 50 frames / sec

        //game loop
        while (!IsGameOver)
        {
            if (IsCollision())
            {
                score += 10;
            }

            DateTime startIterationTime = System.DateTime.Now;
            UpdateGameState();
            Render(); …

当我尝试运行以下脚本时,我不断收到无效的标识符异常:javax.servlet.ServletException:java.sql.SQLException:[Oracle] [ODBC] [Ora] ORA-00904:"CUSTID":标识符无效

   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); 
   conn = DriverManager.getConnection("jdbc:odbc:rreOracle","xxxxxx","xxxxxxxx"); 
   stmt = conn.createStatement(); 
  PreparedStatement preparedStatement;

      //get parameters from the request
      String custID=request.getParameter("cust_ID");
      String saleID=request.getParameter("sale_ID");
      String firstName=request.getParameter("first_Name");
      String mInitial=request.getParameter("mI");
      String lastName=request.getParameter("last_Name");
      String streetName=request.getParameter("street");
      String city=request.getParameter("city");
      String state=request.getParameter("state");
      String zipCode=request.getParameter("zip_Code");
      String DOB=request.getParameter("DOB");
      String agentID=request.getParameter("agent_ID");
      String homePhone=request.getParameter("home_Phone");
      String cellPhone=request.getParameter("cell_Phone");
      String profession=request.getParameter("profession");
      String employer=request.getParameter("employer");
      String referrer=request.getParameter("referrer");


   preparedStatement = conn.prepareStatement("UPDATE customer"
+ " SET customer.cust_ID=?, customer.sale_ID=?, customer.first_Name=?, customer.mI=?, customer.last_Name=?, customer.street_Name=?, customer.city=?, customer.state=?, customer.zip_Code=?,customer. DOB=?, customer.agent_ID=?, customer.home_Phone=?, customer.cell_Phone=?, customer.profession=?, customer.employer=?, customer.referrer=?"
+ " WHERE customer.cust_ID=custID ") ;

   preparedStatement.setInt(1, …

所以基本上,试图弄清楚如何隐藏用户在GUI中输入的值(即java swing,awt)以获取其密码.例如**而不是标准密码.

好吧,我的邪恶编译器一直拒绝我的'='AND'!='重载操作符(我认为)我的Polynomial和Rational类.非常感谢帮助.

using namespace std;

class Polynomial
{

public:

//constructor
Polynomial() 
    {
        for ( int i = 0; i < 100; i++ )
    {
        coefficient[i] = 0;
    }
    }

~Polynomial(){}

void polynomialSet ( Rational a , int b ) //polynomialSetter function
    {  
    coefficient[b] = a;
    exponent = b;
}

    . . . . 

    const Polynomial &Polynomial::operator=(const Polynomial &a)
{
    if (&a == this)
        return *this;
}

bool Polynomial::operator!=(Polynomial &a)
{       
    return !(*this == a);
    }

***************************************************************************
using namespace std;

class Rational …

为什么我的filesize()方法不起作用？我的路径适用于fread()和file()方法,但它不会承认路径filesize().为什么不？我的正确道路应该是什么？

<?php     
    $strLessonDescription = fopen("http://nova.umuc.edu/~ct386a28/lovej2ee/exercise5/content/lesson5.txt", "r") 
                            or die ("Error - lesson5.txt cannot be opened");
    $lessonDescription = fread($strLessonDescription, 
                               filesize("http://nova.umuc.edu/~ct386a28/lovej2ee/exercise5/content/vocabulary5.txt"));
    fclose($strLessonDescription);

    echo $lessonDescription;        
    $arrLessonVocabulary = array();
    $arrLessonVocabulary = file("http://nova.umuc.edu/~ct386a28/lovej2ee/exercise5/content/vocabulary5.txt");

    if (arrLessonVocabulary == NULL)
        print "Error - vocabulary5.txt cannot be opened";
?>

好的,那我的SQL*Plus语句有什么问题？据我所知,一切都应该有效吗？

   //get parameters from the request
 String custID=request.getParameter("cust_ID");
 String saleID=request.getParameter("sale_ID");
 String firstName=request.getParameter("first_Name");
 String mInitial=request.getParameter("mI");
 String lastName=request.getParameter("last_Name");
 String streetName=request.getParameter("street");
 String city=request.getParameter("city");
 String state=request.getParameter("state");
 String zipCode=request.getParameter("zip_Code");
 String DOB=request.getParameter("DOB");
 String agentID=request.getParameter("agent_ID");
 String homePhone=request.getParameter("home_Phone");
 String cellPhone=request.getParameter("cell_Phone");
 String profession=request.getParameter("profession");
 String employer=request.getParameter("emoployer");
 String referrer=request.getParameter("referrer");

 stmt.executeUpdate("INSERT INTO customer 
                         (cust_ID, sale_ID, first_Name, mI, last_Name, street_Name, city, state, zip_Code, DOB, agent_ID, home_Phone, cell_Phone, profession, employer, referrer)"
                    + " VALUES 
                         (custID, saleID, firstName, mInitial, lastName, streetName, city, state, zipCode, DOB, agentID, homePhone, cellPhone, profession, employer, referrer)");

SQL DDL

   CREATE TABLE …

当我清楚地识别出变量时,Oracle一直给我一个无效的标识符错误.

  //get parameters from the request
   String custID=request.getParameter("cust_ID");
   String saleID=request.getParameter("sale_ID");
   String firstName=request.getParameter("first_Name");
   String mInitial=request.getParameter("mI");
   String lastName=request.getParameter("last_Name");
   String streetName=request.getParameter("street");
   String city=request.getParameter("city");
   String state=request.getParameter("state");
   String zipCode=request.getParameter("zip_Code");
   String DOB2=request.getParameter("DOB");
   String agentID=request.getParameter("agent_ID");
   String homePhone=request.getParameter("home_Phone");
   String cellPhone=request.getParameter("cell_Phone");
   String profession=request.getParameter("profession");
   String employer=request.getParameter("employer");
   String referrer=request.getParameter("referrer");


  query =
    "UPDATE customer"
    + " SET customer.cust_ID=custID, customer.sale_ID=saleID, customer.first_Name=firstName, customer.mI=mInitial, customer.last_Name=lastName, customer.street_Name=streetName, customer.city=city, customer.state=state, customer.zip_Code=zipCode,customer. DOB=DOB2, customer.agent_ID=agentID, customer.home_Phone=homePhone, customer.cell_Phone=cellPhone, customer.profession=profession, customer.employer=employer, customer.referrer=referrer"
    + " WHERE customer.cust_ID=custID " ;

  preparedStatement = conn.prepareStatement(query);


  preparedStatement.executeUpdate();

SQL TABLE

        CREATE TABLE customer
          (cust_ID      NUMBER          NOT NULL, …

org.apache.jasper.JasperException: An exception occurred processing JSP page /customerDelete.jsp at line 39

java.lang.NullPointerException
sun.jdbc.odbc.JdbcOdbcPreparedStatement.clearParameter(Unknown Source)

我在尝试

      //get parameters from the request 
      String firstName=request.getParameter("first_Name");  
      String lastName=request.getParameter("last_Name");    


 preparedStatement = conn.prepareStatement("DELETE FROM customer "
                                            + " WHERE customer.first_Name= " +firstName
                    + " AND customer.last_Name= " +lastName);

 preparedStatement.setString(1, firstName); // line 39
 preparedStatement.setString(2, lastName);

 preparedStatement.executeUpdate();

SQL表

          CREATE TABLE customer
    (cust_ID        NUMBER          NOT NULL,
    sale_ID             NUMBER          NOT NULL,
    first_Name      VARCHAR2(30)        NOT NULL,
    mI          VARCHAR2(2)         ,
    last_Name       VARCHAR2(50)        NOT NULL,
    street_Name     VARCHAR2(50)        ,
    city            VARCHAR2(30)        NOT NULL, …