Wednesday, June 27, 2012

Create PHP Image Gallery with MySQL Blob Field

6/27/2012

This is a simple example of photo-gallery script, which uses MySQL table (BLOB field) to store images. Trivial password-protection, uploading and deleting images are supported.

There are three main parts of the script:
  • main page generation --
    generates HTML code for the list of uploaded photos, forms for photo deletion and uploading
  • image uploading --
    processes POST request: checks password, uploads photo to database or deletes it
  • image showing --
    Fetches image information from MySQL database and sends image do browser. If PHP is installed as mod_php (for Apache), does If-Modified-Since HTTP header checking.

Create MySQL / SQL Table

/* 
Online PHP Examples with Source Code
website: http://4evertutorials.blogspot.in/
*/

CREATE TABLE `gallery` ( 
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `title` varchar(64) character SET utf8 NOT NULL,
  `ext` varchar(8) character SET utf8 NOT NULL,
  `image_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `data` mediumblob NOT NULL,
  PRIMARY KEY  (`id`) 
);



You can use any name for this table, just change $table variable at the begining of the image gallery code.
We use following functions in this example:


MySQL
  • mysql_connect - connects to MySQL server
  • mysql_select_db - select database
  • mysql_query - send query
  • mysql_fetch_row - get current row from result table
  • mysql_real_escape_string - escaping string to use it in MySQL query
  • mysql_num_fields - get number of rows
PHP
  • get_magic_quotes_gpc - checking if PHP add slashes before quotes in input parameters
  • stripslashes - remove odd slashes
  • trim - remove unnecessary spaces in the beginning and ending of string
  • getimagesize - return image information as an array. Third element of array -- image type.
  • file_get_contents - loads whole file into memory
  • php_sapi_name - returns the name of PHP Server API
  • apache_request_headers - gets some special header information from Apache
  • strtotime - convert textual representation of time to integer (number of seconds since 1970)
  • header - sends HTTP header to browser
Before using following example create sql-table (execute CREATE TABLE query above) and change variables ($db_host, $db_user, $db_pwd, $database, $table) to your MySQL / database settings.

<?php
/* 
Online PHP Examples with Source Code
website: http://4evertutorials.blogspot.in/
*/
$db_host = 'localhost';  
$db_user = 'username'; 
$db_pwd = 'password';

$database = 'test';
$table = 'gallery'; // use the same name as SQL table

$password = 'pass7';
// simple upload restriction,
// to disallow uploading to everyone


if (!mysql_connect($db_host, $db_user, $db_pwd))
    die("Can't connect to database");

if (!mysql_select_db($database))
    die("Can't select database");

// This function makes usage of
// $_GET, $_POST, etc... variables
// completly safe in SQL queries
function sql_safe($s)
{
    if (get_magic_quotes_gpc())
        $s = stripslashes($s);

    return mysql_real_escape_string($s);
}

// If user pressed submit in one of the forms
if ($_SERVER['REQUEST_METHOD'] == 'POST')
{
    // cleaning title field
    $title = trim(sql_safe($_POST['title']));

    if ($title == '') // if title is not set
        $title = '(empty title)';// use (empty title) string

    if ($_POST['password'] != $password)  // cheking passwors
        $msg = 'Error: wrong upload password';
    else
    {
        if (isset($_FILES['photo']))
        {
            @list(, , $imtype, ) = getimagesize($_FILES['photo']['tmp_name']);
            // Get image type.
            // We use @ to omit errors

            if ($imtype == 3) // cheking image type
                $ext="png";   // to use it later in HTTP headers
            elseif ($imtype == 2)
                $ext="jpeg";
            elseif ($imtype == 1)
                $ext="gif";
            else
                $msg = 'Error: unknown file format';

            if (!isset($msg)) // If there was no error
            {
                $data = file_get_contents($_FILES['photo']['tmp_name']);
                $data = mysql_real_escape_string($data);
                // Preparing data to be used in MySQL query

                mysql_query("INSERT INTO {$table}
                                SET ext='$ext', title='$title',
                                    data='$data'");

                $msg = 'Success: image uploaded';
            }
        }
        elseif (isset($_GET['title']))      // isset(..title) needed
            $msg = 'Error: file not loaded';// to make sure we've using
                                            // upload form, not form
                                            // for deletion


        if (isset($_POST['del'])) // If used selected some photo to delete
        {                         // in 'uploaded images form';
            $id = intval($_POST['del']);
            mysql_query("DELETE FROM {$table} WHERE id=$id");
            $msg = 'Photo deleted';
        }
    }
}
elseif (isset($_GET['show']))
{
    $id = intval($_GET['show']);

    $result = mysql_query("SELECT ext, UNIX_TIMESTAMP(image_time), data
                             FROM {$table}
                            WHERE id=$id LIMIT 1");

    if (mysql_num_rows($result) == 0)
        die('no image');

    list($ext, $image_time, $data) = mysql_fetch_row($result);

    $send_304 = false;
    if (php_sapi_name() == 'apache') {
        // if our web server is apache
        // we get check HTTP
        // If-Modified-Since header
        // and do not send image
        // if there is a cached version

        $ar = apache_request_headers();
        if (isset($ar['If-Modified-Since']) && // If-Modified-Since should exists
            ($ar['If-Modified-Since'] != '') && // not empty
            (strtotime($ar['If-Modified-Since']) >= $image_time)) // and grater than
            $send_304 = true;                                     // image_time
    }


    if ($send_304)
    {
        // Sending 304 response to browser
        // "Browser, your cached version of image is OK
        // we're not sending anything new to you"
        header('Last-Modified: '.gmdate('D, d M Y H:i:s', $ts).' GMT', true, 304);

        exit(); // bye-bye
    }

    // outputing Last-Modified header
    header('Last-Modified: '.gmdate('D, d M Y H:i:s', $image_time).' GMT',
            true, 200);

    // Set expiration time +1 year
    // We do not have any photo re-uploading
    // so, browser may cache this photo for quite a long time
    header('Expires: '.gmdate('D, d M Y H:i:s',  $image_time + 86400*365).' GMT',
            true, 200);

    // outputing HTTP headers
    header('Content-Length: '.strlen($data));
    header("Content-type: image/{$ext}");

    // outputing image
    echo $data;
    exit();
}
?>
<html><head>
<title>Create PHP Image Gallery with MySQL Blob Field</title>
</head>
<body>
<?php
if (isset($msg)) // this is special section for
                 // outputing message
{
?>
<p style="font-weight: bold;"><?=$msg?>
<br>
<a href="<?=$PHP_SELF?>">reload page</a>
<!-- I've added reloading link, because
     refreshing POST queries is not good idea -->
</p>
<?php
}
?>
<h1>PHP-MySQL Image Gallery</h1>
<h2>Uploaded images:</h2>
<form action="<?=$PHP_SELF?>" method="post">
<!-- This form is used for image deletion -->

<?php
$result = mysql_query("SELECT id, image_time, title FROM {$table} ORDER BY id DESC");
if (mysql_num_rows($result) == 0) // table is empty
    echo '<ul><li>No images loaded</li></ul>';
else
{
    echo '<ul>';
    while(list($id, $image_time, $title) = mysql_fetch_row($result))
    {
        // outputing list
        echo "<li><input type='radio' name='del' value='{$id}'>";
        echo "<a href='{$PHP_SELF}?show={$id}'>{$title}</a> – ";
        echo "<small>{$image_time}</small></li>";
    }

    echo '</ul>';

    echo '<label for="password">Password:</label><br>';
    echo '<input type="password" name="password" id="password"><br><br>';

    echo '<input type="submit" value="Delete selected">';
}
?>

</form>
<h2>Upload new image:</h2>
<form action="<?=$PHP_SELF?>" method="POST" enctype="multipart/form-data">
<label for="title">Title:</label><br>
<input type="text" name="title" id="title" size="64"><br><br>

<label for="photo">Photo:</label><br>
<input type="file" name="photo" id="photo"><br><br>

<label for="password">Password:</label><br>
<input type="password" name="password" id="password"><br><br>

<input type="submit" value="upload">
</form>
</body>
</html>


helpful? Share this

The Editorial Team of 4everTutorials consists of a group of PHP Professionals.

0 comments:

 

© 2014 4everTutorials. All rights resevered.

Back To Top