我们目前有一个投票系统设置，可以保存投票人的 IP 地址以阻止重复投票。
然而，每天都会从数据库中删除 IP 地址，这样他们就可以对最喜欢的项目重新投票。
看看下面的代码，你能看到我如何阻止这种情况，这样一个拥有特定 IP 地址的人就再也不能投票给那个特定的项目了吗？然而，他们可以对其他参赛者进行投票，但同样只能投票一次。
有任何想法吗？
<?php
// Script Voting - http://www.coursesweb.net/
class Voting {
// properties
static protected $conn = false; // stores the connection to mysql
public $affected_rows = 0; // number of affected, or returned rows in SQL query
protected $voter = ''; // the user who vote, or its IP
protected $nrvot = 0; // if it is 1, the user can vote only one item in a day, 0 for multiple items
protected $svoting = 'mysql'; // 'mysql' to register data in database, any other value register in TXT files
public $votitems = 'voting'; // Table /or file_name to store items that are voted
public $votusers = 'votusers'; // Table /or filename that stores the users who voted in current day
protected $tdy; // will store the number of current day
public $eror = false; // to store and check for errors
// constructor
public function __construct() {
// sets $nrvot, $svoting, $voter, and $tdy properties
if(defined('NRVOT')) $this->nrvot = NRVOT;
if(defined('SVOTING')) $this->svoting = SVOTING;
if(defined('USRVOTE') && USRVOTE === 0) { if(defined('VOTER')) $this->voter = VOTER; }
else $this->voter = $_SERVER['REMOTE_ADDR'];
$this->tdy = date('j');
// if set to use TXT files, set the path and name of the files
if($this->svoting != 'mysql') {
$this->votitems = '../votingtxt/'.$this->votitems.'.txt';
$this->votusers = '../votingtxt/'.$this->votusers.'.txt';
}
}
// for connecting to mysql
protected function setConn() {
try {
// Connect and create the PDO object
self::$conn = new PDO("mysql:host=".DBHOST."; dbname=".DBNAME, DBUSER, DBPASS);
// Sets to handle the errors in the ERRMODE_EXCEPTION mode
self::$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
self::$conn->exec('SET CHARACTER SET utf8'); // Sets encoding UTF-8
}
catch(PDOException $e) {
$this->eror = 'Unable to connect to MySQL: '. $e->getMessage();
}
}
// Performs SQL queries
public function sqlExecute($sql) {
if(self::$conn===false OR self::$conn===NULL) $this->setConn(); // sets the connection to mysql
$re = true; // the value to be returned
// if there is a connection set ($conn property not false)
if(self::$conn !== false) {
// gets the first word in $sql, to determine whenb SELECT query
$ar_mode = explode(' ', trim($sql), 2);
$mode = strtolower($ar_mode[0]);
// performs the query and get returned data
try {
if($sqlprep = self::$conn->prepare($sql)) {
// execute query
if($sqlprep->execute()) {
// if $mode is 'select', gets the result_set to return
if($mode == 'select') {
$re = array();
// if fetch() returns at least one row (not false), adds the rows in $re for return
if(($row = $sqlprep->fetch(PDO::FETCH_ASSOC)) !== false){
do {
// check each column if it has numeric value, to convert it from "string"
foreach($row AS $k=>$v) {
if(is_numeric($v)) $row[$k] = $v + 0;
}
$re[] = $row;
}
while($row = $sqlprep->fetch(PDO::FETCH_ASSOC));
}
$this->affected_rows = count($re); // number of returned rows
}
}
else $this->eror = 'Cannot execute the sql query';
}
else {
$eror = self::$conn->errorInfo();
$this->eror = 'Error: '. $eror[2];
}
}
catch(PDOException $e) {
$this->eror = $e->getMessage();
}
}
// sets to return false in case of error
if($this->eror !== false) { echo $this->eror; $re = false; }
return $re;
}
// returns JSON string with item:['vote', 'nvotes', renot] for each element in $items array
public function getVoting($items, $vote = '') {
$votstdy = $this->votstdyCo($items); // gets from Cookie array with items voted by the user today
// if $vote not empty, perform to register the vote, $items contains one item to vote
if(!empty($vote)) {
// if $voter empty means user not loged
if($this->voter === '') return "alert('Vote Not registered.\\nYou must be logged in to can vote')";
else {
// gets array with items voted today from mysql, or txt-files (according to $svoting), and merge unique to $votstdy
if($this->svoting == 'mysql') {
$votstdy = array_unique(array_merge($votstdy, $this->votstdyDb()));
}
else {
$all_votstdy = $this->votstdyTxt(); // get 2 array: 'all'-rows voted today, 'day'-items by voter today
$votstdy = array_unique(array_merge($votstdy, $all_votstdy[$this->tdy]));
}
// if already voted, add in cookie, returns JSON from which JS alert message and will reload the page
// else, accesses the method to add the new vote, in mysql or TXT file
if(in_array($items[0], $votstdy) || ($this->nrvot === 1 && count($votstdy) > 0)) {
$votstdy[] = $items[0];
setcookie("votings", implode(',', array_unique($votstdy)), strtotime('tomorrow'));
return '{"'.$items[0].'":[0,0,3]}';
}
else if($this->svoting == 'mysql') $this->setVotDb($items, $vote, $votstdy); // add the new vote in mysql
else $this->setVotTxt($items, $vote, $all_votstdy); // add the new vote, and voter in TXT files
array_push($votstdy, $items[0]); // adds curent item as voted
}
}
// if $nrvot is 1, and $votstdy has item, set $setvoted=1 (user already voted today)
// else, user can vote multiple items, after Select is checked if already voted the existend $item
$setvoted = ($this->nrvot === 1 && count($votstdy) > 0) ? 1 : 0;
// get array with items and their votings from mysql or TXT file
$votitems = ($this->svoting == 'mysql') ? $this->getVotDb($items, $votstdy, $setvoted) : $this->getVotTxt($items, $votstdy, $setvoted);
return json_encode($votitems);
}
// insert /update rating item in #votitems, delete rows in $votusers which are not from today, insert $voter in $votusers
protected function setVotDb($items, $vote, $votstdy) {
$this->sqlExecute("INSERT INTO `$this->votitems` (`item`, `vote`) VALUES ('".$items[0]."', $vote) ON DUPLICATE KEY UPDATE `vote`=`vote`+$vote, `nvotes`=`nvotes`+1");
$this->sqlExecute("DELETE FROM `$this->votusers` WHERE `day`!=$this->tdy");
$this->sqlExecute("INSERT INTO `$this->votusers` (`day`, `voter`, `item`) VALUES ($this->tdy, '$this->voter', '".$items[0]."')");
// add curent voted item to the others today, and save them as string ',' in cookie (till the end of day)
$votstdy[] = $items[0];
setcookie("votings", implode(',', array_unique($votstdy)), strtotime('tomorrow'));
}
// select 'vote' and 'nvotes' of each element in $items, $votstdy stores items voted by the user today
// returns array with item:['vote', 'nvotes', renot] for each element in $items array
protected function getVotDb($items, $votstdy, $setvoted) {
$re = array_fill_keys($items, array(0,0,$setvoted)); // makes each value of $items as key with an array(0,0,0)
function addSlhs($elm){return "'".$elm."'";} // function to be used in array_map(), adds "'" to each $elm
$resql = $this->sqlExecute("SELECT * FROM `$this->votitems` WHERE `item` IN(".implode(',', array_map('addSlhs', $items)).")");
if($this->affected_rows > 0) {
for($i=0; $i<$this->affected_rows; $i++) {
$voted = in_array($resql[$i]['item'], $votstdy) ? $setvoted + 1 : $setvoted; // add 1 if the item was voted by the user today
$re[$resql[$i]['item']] = array($resql[$i]['vote'], $resql[$i]['nvotes'], $voted);
}
}
return $re;
}
// add /update rating item in TXT file, keep rows from today in $votusers, and add new row with $voter
protected function setVotTxt($items, $vote, $all_votstdy) {
// get the rows from file with items, if exists
if(file_exists($this->votitems)) {
$rows = file($this->votitems, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
$nrrows = count($rows);
// if exist rows registered, get array for each row, with - item^vote^nvotes
// if row with item, update it and stop, else, add the row at the end
if($nrrows > 0) {
for($i=0; $i<$nrrows; $i++) {
$row = explode('^', $rows[$i]);
if($row[0] == $items[0]) {
$rows[$i] = $items[0].'^'.($row[1] + $vote).'^'.($row[2] + 1);
$rowup = 1; break;
}
}
}
}
if(!isset($rowup)) $rows[] = $items[0].'^'.$vote.'^1';
file_put_contents($this->votitems, implode(PHP_EOL, $rows)); // save the items in file
// add row with curent item voted and the voter (today^voter^item), and save all the rows
$all_votstdy['all'][] = $this->tdy.'^'.$this->voter.'^'.$items[0];
file_put_contents($this->votusers, implode(PHP_EOL, $all_votstdy['all']));
// add curent voted item to the others today, and save them as string ',' in cookie (till the end of day)
$all_votstdy[$this->tdy][] = $items[0];
setcookie("votings", implode(',', array_unique($all_votstdy[$this->tdy])), strtotime('tomorrow'));
}
// get from TXT 'vote' and 'nvotes' of each element in $items, $votstdy stores items voted by the user today
// returns array with item:['vote', 'nvotes', renot] for each element in $items array
protected function getVotTxt($items, $votstdy, $setvoted) {
$re = array_fill_keys($items, array(0,0,$setvoted)); // makes each value of $items as key with an array(0,0,0)
if(file_exists($this->votitems)) {
$rows = file($this->votitems, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
$nrrows = count($rows);
// if exist rows registered, get array for each row, with - item^vote^nvotes
// if row with item is in $items, add its data in $re
if($nrrows > 0) {
for($i=0; $i<$nrrows; $i++) {
$row = explode('^', $rows[$i]);
$voted = in_array($row[0], $votstdy) ? $setvoted + 1 : $setvoted; // add 1 if the item was voted by the user today
if(in_array($row[0], $items)) $re[$row[0]] = array($row[1], $row[2], $voted);
}
}
}
return $re;
}
// gets and returns from Cookie an array with items voted by the user ($voter) today
protected function votstdyCo() {
$votstdy = array();
// if exists cookie 'votings', adds items voted today in $votstdy (array_filter() - removes null, empty elements)
if(isset($_COOKIE['votings'])) {
$votstdy = array_filter(explode(',', $_COOKIE['votings'])); // cookie stores string with: item1, item2, ...
}
return $votstdy;
}
// returns from mysql an array with items voted by the user today
protected function votstdyDb() {
$votstdy = array();
$resql = $this->sqlExecute("SELECT `item` FROM `$this->votusers` WHERE `day`=$this->tdy AND `voter`='$this->voter'");
if($this->affected_rows > 0) {
for($i=0; $i<$this->affected_rows; $i++) {
$votstdy[] = $resql[$i]['item'];
}
}
return $votstdy;
}
// returns from TXT file an array with 2 arrays: all rows voted today, and items voted by the user today
protected function votstdyTxt() {
$re['all'] = array(); $re[$this->tdy] = array();
if(file_exists($this->votusers)) {
$rows = file($this->votusers, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
$nrrows = count($rows);
// if exist rows registered, get array for each row, with - day^voter^item , compare 'day', and 'voter'
if($nrrows > 0) {
for($i=0; $i<$nrrows; $i++) {
$row = explode('^', $rows[$i]);
if($row[0] == $this->tdy) {
$re['all'][] = $rows[$i];
if($row[1] == $this->voter) $re[$this->tdy][] = $row[2];
}
}
}
}
return $re;
}
}