PHP MySQL example: image gallery (blob-storage)

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PHP MySQL example: image gallery (blob-storage)

abstract

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. For Apache-version of PHP there is advanced browser-caching support (using If-Modified-Since header).

compatible

PHP 4.3.0 or higher

PHP 5

There are three notable 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.

Image gallery example uses following table to store all of its data:

 CREATE TABLE `ae_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

You can get help on this functions typing "php function-name" in any good search engine

Before using following example create sql-table (execute CREATE TABLE query above) andchange variables ($db_host, $db_user, $db_pwd, $database, $table) to your MySQL / database settings.

<?php$db_host = 'localhost'; // don't forget to change $db_user = 'mysql-user'; $db_pwd = 'mysql-password';$database = 'test';$table = 'ae_gallery';// use the same name as SQL table$password = '123';// simple upload restriction,// to disallow uploading to everyoneif (!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, $_POST, etc... variables// completly safe in SQL queriesfunction sql_safe($s){    if (get_magic_quotes_gpc())        $s = stripslashes($s);    return mysql_real_escape_string($s);}// If user pressed submit in one of the formsif ($_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 $data;    exit();}?><html><head><title>MySQL Blob Image Gallery Example</title></head><body><?phpif (isset($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>Blob 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> &ndash; ";        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>

warning

By default, PHP does not allow uploading files larger than 2Mb. Uploading of large photos fail if you will not change upload-max-filesize and post-max-size directives.

Don't forget to change default password, or use some other authentication method.

tested

FreeBSD 5.2 :: PHP 5.1.4

Linux CentOS 4.0 :: PHP 4.4.4

下面几条也许可以帮助你储存小于24MB的文件：修改 store.php3 ，将 MAX_FILE_SIZE 的值改成 24000000。修改你的PHP设置，在一般情况下，PHP只允许小于2MB的文件，你必须将max_filesize（在php.ini中）的值改成24000000 去掉MYSQL的数据包大小限制,在一般情况下 MYSQL 小于1 MB的数据包. 你必须用以下参数重启你的MYSQL /usr/local/bin/safe_mysqld -O key_buffer=16M -O table_cache=128 -O sort_buffer=4M -O record_buffer=1M -O max_allowed_packet=24M 如果仍然出错：可能是超时错误，如果你通过一个很慢的连接来储存一个很大的文件，PHP缺省的时间限制为30秒。你可以将max_execution_time(在php.ini中)的值改为-1