如何在大学综合门户中添加下载功能

嘿，大家好！今天我们要聊的是如何在大学综合门户网站上添加一个下载功能。想象一下，学生们可以直接从你的网站上下载学习资料、课件或者考试大纲，这该有多方便啊！接下来，我会教大家如何用PHP和MySQL来实现这个功能。

第一步：准备数据库

首先，我们需要一个数据库来存储文件的信息。这里我们用MySQL数据库。

CREATE TABLE `files` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `filename` varchar(255) NOT NULL,
  `file_path` varchar(255) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

第二步：上传文件

现在让我们创建一个表单，让学生们可以上传文件到服务器。

<form action="upload.php" method="post" enctype="multipart/form-data">
    Select file to upload:
    <input type="file" name="fileToUpload" id="fileToUpload">
    <input type="submit" value="Upload File" name="submit">
</form>

第三步：处理上传

编写upload.php文件来处理文件上传，并将其存储在服务器上。

<?php
$target_dir = "uploads/";
$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);
$uploadOk = 1;
$imageFileType = strtolower(pathinfo($target_file,PATHINFO_EXTENSION));
// Check if image file is a actual image or fake image
if(isset($_POST["submit"])) {
  $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
  if($check !== false) {
    echo "File is an image - " . $check["mime"] . ".";
    $uploadOk = 1;
  } else {
    echo "File is not an image.";
    $uploadOk = 0;
  }
}
// Check if file already exists
if (file_exists($target_file)) {
  echo "Sorry, file already exists.";
  $uploadOk = 0;
}
// Check file size
if ($_FILES["fileToUpload"]["size"] > 500000) {
  echo "Sorry, your file is too large.";
  $uploadOk = 0;
}
// Allow certain file formats
if($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg"
&& $imageFileType != "gif" ) {
  echo "Sorry, only JPG, JPEG, PNG & GIF files are allowed.";
  $uploadOk = 0;
}
// Check if $uploadOk is set to 0 by an error
if ($uploadOk == 0) {
  echo "Sorry, your file was not uploaded.";
// if everything is ok, try to upload file
} else {
  if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file)) {
    echo "The file ". htmlspecialchars( basename( $_FILES["fileToUpload"]["name"])). " has been uploaded.";
    
    // Store file information in the database
    $conn = new mysqli('localhost', 'username', 'password', 'database');
    if ($conn->connect_error) {
        die("Connection failed: " . $conn->connect_error);
    }
    $sql = "INSERT INTO files (filename, file_path) VALUES ('".$_FILES["fileToUpload"]["name"]."', '".$target_file."')";
    if ($conn->query($sql) === TRUE) {
        echo "New record created successfully";
    } else {
        echo "Error: " . $sql . "<br>" . $conn->error;
    }
    $conn->close();
  } else {
    echo "Sorry, there was an error uploading your file.";
  }
}
?>

第四步：创建下载链接

融合门户

最后一步是创建一个页面，列出所有可下载的文件，并提供下载链接。

<?php
$conn = new mysqli('localhost', 'username', 'password', 'database');
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT * FROM files";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        echo "Name: " . $row['filename']. " - Download Link: <a href='".$row['file_path']."'>Download</a><br>";
    }
} else {
    echo "0 results";
}
$conn->close();
?>

好了，这就是全部内容了。现在你已经知道如何在大学综合门户上添加下载功能了。希望这对大家有所帮助！如果有任何问题，欢迎随时提问。

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