PHP and SQLite: How to handle images and multimedia files

PHP and SQLite: How to handle images and multimedia files

Introduction:
In modern websites and applications, processing images and multimedia files are very common tasks. PHP is a popular server-side scripting language, while SQLite is a lightweight embedded database engine. This article will explain how to use PHP and SQLite together to effectively process images and multimedia files.

1. Create a SQLite database
First, we need to create a SQLite database to store information related to images and multimedia files. Databases can be created using the SQLite command line tool or SQLite's PHP extension library.

The following is an example of using the SQLite command line tool to create a database:

$ sqlite3 media.db
SQLite version 3.31.1 20...
Enter ".help" for usage hints.

sqlite> CREATE TABLE media (
   id INTEGER PRIMARY KEY,
   filename TEXT NOT NULL,
   type TEXT NOT NULL,
   filepath TEXT NOT NULL
);
sqlite> .quit

In the above example, we created a database named media.db, And created a table named media, which contains id, filename, type and filepath Four columns.

2. Upload images and multimedia files
Next, we need to write PHP code to process the uploaded images and multimedia files. First, we need an HTML form that users can use to upload files. The following is a simple form example:

<form action="upload.php" method="post" enctype="multipart/form-data">
   <input type="file" name="file">
   <input type="submit" value="Upload">
</form>

In the above form, we used enctype="multipart/form-data" to support file upload. name="file" defines the form field name for uploading files.

Next, we need to write a PHP script named upload.php to process the uploaded file. The following is a simple script example:

<?php
if(isset($_FILES['file'])) {
   $file = $_FILES['file'];
   $filename = $file['name'];
   $filetype = $file['type'];
   $filesize = $file['size'];
   $tmpname = $file['tmp_name'];
   
   $filepath = 'uploads/'. $filename;
   
   move_uploaded_file($tmpname, $filepath);
   
   // 插入文件信息到SQLite数据库
   $db = new SQLite3('media.db');
   $stmt = $db->prepare("INSERT INTO media (filename, type, filepath) VALUES (:filename, :type, :filepath)");
   $stmt->bindValue(':filename', $filename, SQLITE3_TEXT);
   $stmt->bindValue(':type', $filetype, SQLITE3_TEXT);
   $stmt->bindValue(':filepath', $filepath, SQLITE3_TEXT);
   $stmt->execute();
   
   echo "文件上传成功！";
}
?>

In the above code, we use $_FILES['file'] to access related information of the uploaded file, such as file name, type, size and temporary path. We then move the file to the specified directory on the server and insert the file information into the SQLite database.

3. Display images and multimedia files
Finally, we need to write code to retrieve file information from the SQLite database and display images and multimedia files on the web page. The following is a simple PHP script example:

<?php
$db = new SQLite3('media.db');
$stmt = $db->prepare("SELECT * FROM media");
$result = $stmt->execute();

while($row = $result->fetchArray(SQLITE3_ASSOC)) {
   $filepath = $row['filepath'];
   $filetype = $row['type'];
   
   if($filetype === 'image/jpeg' || $filetype === 'image/png') {
      echo "<img src='$filepath' alt=''>";
   }
   elseif($filetype === 'audio/mpeg') {
      echo "<audio controls><source src='$filepath' type='audio/mpeg'></audio>";
   }
   elseif($filetype === 'video/mp4') {
      echo "<video controls><source src='$filepath' type='video/mp4'></video>";
   }
}
?>

In the above code, we retrieve all the file information from the SQLite database and based on the file type, use HTML's <img>, <audio> or <video> tags to display images and multimedia files.

Conclusion:
By using PHP and SQLite together, we can effectively process images and multimedia files. We can upload files to a specified directory on the server and store the file information in a SQLite database. We can then retrieve the file information from the database and display the images and multimedia files on the web page.

The above are examples of PHP and SQLite applications on how to process images and multimedia files. By using these technologies, we can easily implement the management and display functions of images and multimedia files in websites or applications.

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