Javascript 星级系统-连接js与PHP和MySQL

我有这个

以及连接以下各项的PHP文件（rating.PHP）：

<?php

// Error function that stops script processing with die
function error($message){
    $output = json_encode(
        array(
            'result' => 'error',
            'msg' => $message
        )
    );
    die($output);
}

// Round to the nearest 0.5
function roundToNearestHalf($number){
    return round($number * 2) / 2;  
}

// Instantiate database connection
$db = new mysqli('localhost', 'root', 'XXX', 'XXX');

// Check that the connection worked
if($db->connect_errno > 0){
    error('Unable to connect to database [' . $db->connect_error . ']');
}

// Verify that we have enough post items
if(count($_POST) > 1){
    error('Too many post items received.');
}

// Check that the rating was entered
if(!isset($_POST['rating']) || $_POST['rating'] == ''){
    error('No rating value provided.');
}

// Valid the rating amount that was entered.
if(!preg_match("/[0-5](?:\.5)/", $_POST['rating']) && $_POST['rating'] < 0 && $_POST['rating'] > 5){
    error('Invalid rating provided.');
}

// Check if the user has rated before
$sql = <<<SQL
    SELECT `ratingid`
    FROM `ratings`
    WHERE `ip` = '{$_SERVER['REMOTE_ADDR']}'
SQL;

if(!$result = $db->query($sql)){
    error('There was an error running the query [' . $db->error . ']');
}

// Tell the user that they have voted already.
if($result->num_rows){
    error('That IP address has already voted, please try using another IP.');
}

// Store the user's rating.
$rating = $db->escape_string($_POST['rating']);

$sql = <<<SQL
    INSERT INTO `ratings`
    (`rating`, `ip`)
    VALUES ('{$rating}', '{$_SERVER['REMOTE_ADDR']}')
SQL;

if(!$db->query($sql)){
    error('Unable to insert rating to database [' . $db->error . ']');
}

// Get the average rating
$sql = <<<SQL
    SELECT AVG(`rating`) AS `rating`
    FROM `ratings`
SQL;

if(!$result = $db->query($sql)){
    error('There was an error running the query [' . $db->error . ']');
}

// Fetch the average rating
$data = $result->fetch_assoc();

$rating = $data['rating'];

// Output the average rating for the front end to handle
$output = json_encode(
    array(
        'result' => 'success',
        'rating' => roundToNearestHalf($rating)
    )
);
echo $output;
?>

---

您的评分表没有为哪个项目评分的字段？好吧，现在我只是测试是否收到数据，解决了这个问题后，我将把我的表与产品和估价联系起来。这可能是因为没有将它们关联到first？你能帮我吗？感谢错误消息所指的行是什么？文件结尾：“？>”-“未找到元素”rating.php:93:3
CREATE TABLE `rating` (
    `ratingid` INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
    `rating` FLOAT UNSIGNED NOT NULL,
    `time` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    `ip` VARCHAR( 39 ) NOT NULL,
    UNIQUE (`ip`)
) ENGINE = INNODB

<?php

// Error function that stops script processing with die
function error($message){
    $output = json_encode(
        array(
            'result' => 'error',
            'msg' => $message
        )
    );
    die($output);
}

// Round to the nearest 0.5
function roundToNearestHalf($number){
    return round($number * 2) / 2;  
}

// Instantiate database connection
$db = new mysqli('localhost', 'root', 'XXX', 'XXX');

// Check that the connection worked
if($db->connect_errno > 0){
    error('Unable to connect to database [' . $db->connect_error . ']');
}

// Verify that we have enough post items
if(count($_POST) > 1){
    error('Too many post items received.');
}

// Check that the rating was entered
if(!isset($_POST['rating']) || $_POST['rating'] == ''){
    error('No rating value provided.');
}

// Valid the rating amount that was entered.
if(!preg_match("/[0-5](?:\.5)/", $_POST['rating']) && $_POST['rating'] < 0 && $_POST['rating'] > 5){
    error('Invalid rating provided.');
}

// Check if the user has rated before
$sql = <<<SQL
    SELECT `ratingid`
    FROM `ratings`
    WHERE `ip` = '{$_SERVER['REMOTE_ADDR']}'
SQL;

if(!$result = $db->query($sql)){
    error('There was an error running the query [' . $db->error . ']');
}

// Tell the user that they have voted already.
if($result->num_rows){
    error('That IP address has already voted, please try using another IP.');
}

// Store the user's rating.
$rating = $db->escape_string($_POST['rating']);

$sql = <<<SQL
    INSERT INTO `ratings`
    (`rating`, `ip`)
    VALUES ('{$rating}', '{$_SERVER['REMOTE_ADDR']}')
SQL;

if(!$db->query($sql)){
    error('Unable to insert rating to database [' . $db->error . ']');
}

// Get the average rating
$sql = <<<SQL
    SELECT AVG(`rating`) AS `rating`
    FROM `ratings`
SQL;

if(!$result = $db->query($sql)){
    error('There was an error running the query [' . $db->error . ']');
}

// Fetch the average rating
$data = $result->fetch_assoc();

$rating = $data['rating'];

// Output the average rating for the front end to handle
$output = json_encode(
    array(
        'result' => 'success',
        'rating' => roundToNearestHalf($rating)
    )
);
echo $output;
?>