PHP 似乎没有处理要发布到 MySQL 的脚本

Question

我正在使用 html5 canvas 捕获签名并将其存储在 MySQL 中。除了保存签名并将其发送到 MySQL 的部分外，脚本中的所有内容都可以正常工作。 我对 AJAX 一无所知，所以我正在研究我在书中读到的内容，查看教程并从这里获得帮助。

所以在 Firefox 控制台中，当我点击保存签名时，我可以看到脚本显示了它应该去的 post.php 文件并显示了一个 200 ok 通知，但是没有任何反应，它没有在 MySQL 中发布(它没有不要让我感到惊讶，因为我确定我的代码不正确)并且我没有看到任何错误。

我要完成的是将签名图片上传到服务器上的一个文件夹中，并将图片的路径保存在MySQL中。由于不熟悉 JavaScript、Jquery 和 Ajax，我对如何让它发挥作用感到困惑。

这是 jquery:

$(document).ready(function () {
/** Set Canvas Size **/
var canvasWidth = 400;
var canvasHeight = 75;

/** IE SUPPORT **/
var canvasDiv = document.getElementById('signaturePad');
canvas = document.createElement('canvas');
canvas.setAttribute('width', canvasWidth);
canvas.setAttribute('height', canvasHeight);
canvas.setAttribute('id', 'canvas');
canvasDiv.appendChild(canvas);
if (typeof G_vmlCanvasManager != 'undefined') {
    canvas = G_vmlCanvasManager.initElement(canvas);
}
var context = canvas.getContext("2d");

var clickX = new Array();
var clickY = new Array();
var clickDrag = new Array();
var paint;

/** Redraw the Canvas **/
function redraw() {
    canvas.width = canvas.width; // Clears the canvas

    context.strokeStyle = "#000000";
    context.lineJoin = "miter";
    context.lineWidth = 2;

    for (var i = 0; i < clickX.length; i++) {
        context.beginPath();
        if (clickDrag[i] && i) {
            context.moveTo(clickX[i - 1], clickY[i - 1]);
        } else {
            context.moveTo(clickX[i] - 1, clickY[i]);
        }
        context.lineTo(clickX[i], clickY[i]);
        context.closePath();
        context.stroke();
    }
}

/** Save Canvas **/
$("#saveSig").click(function saveSig() {
    //encode URI
    var sigData = encodeURIComponent(canvas.toDataURL("image/png"));
$("#imgData").html('Thank you! Your signature was saved');
    var ajax = XMLHttpRequest();
    ajax.open("POST", 'post.php');
    ajax.setRequestHeader('Content-Type', 'application/upload');
    ajax.send(sigData);
   // $('#debug').html(sigData);
});

/** Clear Canvas **/
$('#clearSig').click(
    function clearSig() {
        clickX = new Array();
        clickY = new Array();
        clickDrag = new Array();
        context.clearRect(0, 0, canvas.width, canvas.height);
});

/**Draw when moving over Canvas **/
$('#signaturePad').mousemove(function (e) {
    if (paint) {
        addClick(e.pageX - this.offsetLeft, e.pageY - this.offsetTop, true);
        redraw();
    }
});

/**Stop Drawing on Mouseup **/
$('#signaturePad').mouseup(function (e) {
    paint = false;
});

/** Starting a Click **/
function addClick(x, y, dragging) {
    clickX.push(x);
    clickY.push(y);
    clickDrag.push(dragging);
}

$('#signaturePad').mousedown(function (e) {
    var mouseX = e.pageX - this.offsetLeft;
    var mouseY = e.pageY - this.offsetTop;

    paint = true;
    addClick(e.pageX - this.offsetLeft, e.pageY - this.offsetTop);
    redraw();
});

});

这是 PHP:此外，我没有在下面编写 PHP 代码，它是整个签名板的一部分，所以我确定它不正确。

<?php
session_start();
if (isset($GLOBALS["HTTP_RAW_POST_DATA"]))
{
$session_id = $_SERVER['REMOTE_ADDR'];
// Get the data
$imageData=$GLOBALS['HTTP_RAW_POST_DATA'];

// Remove the headers (data:,) part.
// A real application should use them according to needs such as to check image type
$filteredData=substr($imageData, strpos($imageData, ",")+1);

// Need to decode before saving since the data we received is already base64 encoded
$unencodedData=base64_decode($filteredData);

//echo "unencodedData".$unencodedData;
$imageName = "sign_" . rand(5,1000) . rand(1, 10) . rand(10000, 150000) . rand(1500,   100000000) . ".png";
//Set the absolute path to your folder (i.e. /usr/home/your-domain/your-folder/
$filepath = "xampp/htdocs/alpha/site7/images/" . $imageName;

$fp = fopen("$filepath", 'wb' );
fwrite( $fp, $unencodedData);
fclose( $fp );

//Connect to a mySQL database and store the user's information so you can link to it later
$link = mysql_connect('localhost','root', 'password') OR DIE(mysql_error);
mysql_select_db("customer", $link);
mysql_query("INSERT INTO 'signature' ('session', 'image_location') VALUES       ('$session_id', '$imageName')") OR DIE(mysql_error());
mysql_close($link);
}
?>

和 html:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
<title>Signature Pad</title>

<!-- The Signature Pad -->
<script type ="text/javascript" src="jquery.min.js"></script>
<script type="text/javascript" src="signature-pad.js"></script>
</head>
<body>
<center>
<fieldset style="width: 435px">
    <br/>
    <br/>
    <div id="signaturePad" style="border: 1px solid #ccc; height: 55px; width: 400px;"></div>
    <br/>
    <button id="clearSig" type="button">Clear Signature</button>&nbsp;
    <button id="saveSig" type="button">Save Signature</button>
    <div id="imgData"></div>
    <div 
    <br/>
    <br/>
</fieldset>
</center>
<div id="debug"></div>
</body>
</html>

经过一番苦思冥想之后，我终于能够发现一些错误。 在签名板上签名并按下保存签名按钮后，我在 Firebug 中收到这些错误

Warning: fopen(xampp/htdocs/alpha/site6/images/sign_42281643871777767.png): failed to open stream: No such file or directory in C:\xampp\htdocs\alpha\site6\post.php on line 20

Warning: fwrite() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\alpha\site6\post.php on line 21

Warning: fclose() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\alpha\site6\post.php on line 22
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''signatures' ('session', 'image_location') VALUES ('127.0.0.1', 'sign_42281643871' at line 1

由于我对 Jquery 或 Ajax 以及它们如何创建图像并尝试将其发布到文件夹一无所知，所以我几乎无法理解这一点!

Answer 1

似乎我在回答我自己的问题，我已经弄清楚 fopen 错误是什么，我没有使用绝对路径所以在路径开始之前添加/清除了除最后一个错误之外的所有内容这: 您的 SQL 语法有误；检查与您的 MySQL 服务器版本对应的手册，了解在第 1 行的 ''signature' ('session', 'image_location') VALUES ('127.0.0.1', 'sign_11814198867') 附近使用的正确语法