PHP MySQL example: image gallery (blob-storage)
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 |
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:
source code: MySQL / SQL
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 $table variable at the begining of the image gallery code.
We use following functions in this example:
MySQL
- mysql_connect - connects to MySQL server
- mysql_select_db - select database
- mysql_query - send query
- mysql_fetch_row - get current row from result table
- mysql_real_escape_string - escaping string to use it in MySQL query
- mysql_num_fields - get number of rows
- get_magic_quotes_gpc - checking if PHP add slashes before quotes in input parameters
- stripslashes - remove odd slashes
- trim - remove unnecessary spaces in the beginning and ending of string
- getimagesize - return image information as an array. Third element of array -- image type.
- file_get_contents - loads whole file into memory
- php_sapi_name - returns the name of PHP Server API
- apache_request_headers - gets some special header information from Apache
- strtotime - convert textual representation of time to integer (number of seconds since 1970)
- header - sends HTTP header to browser
You can get help on this functions typing "php function-name" in any good search engine
Before using following example create sql-table (execute CREATE TABLE query above) andchange variables ($db_host, $db_user, $db_pwd, $database, $table) to your MySQL / database settings.
source code: php
<?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 $password = '123'; // simple upload restriction, // to disallow uploading to everyone if (!mysql_connect($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 $data; exit(); } ?> <html><head>
<title>MySQL Blob Image Gallery Example</title>
</head>
<body>
<?php if (isset($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>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> – "; 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 |
| tested |