php显示数据库图片不显示(php表格显示数据库信息)

Introduction

PHP is a popular programming language for developing web applications. One common feature of web applications is the display of images on web pages. These images could be stored in a database or in a server file system. In this article, we will discuss the issue of PHP not displaying database images.

Database Configuration

To store images in a database, we first need to configure the database to allow this type of data. When creating the table to store images, we need to specify the column type as BLOB (Binary Large OBject) to indicate that the column will store binary data such as images. For example, the following SQL statement creates a table with a BLOB column:

CREATE TABLE `images` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `image` blob,
  PRIMARY KEY (`id`)
);

Once the table is created, we can insert images into the database using PHP. The PHP code to insert an image into the database would look something like this:

$image = file_get_contents("path/to/image.jpg");
$name = "image.jpg";

$stmt = $pdo->prepare("INSERT INTO images (name, image) VALUES (:name, :image)");
$stmt->bindParam(':name', $name);
$stmt->bindParam(':image', $image, PDO::PARAM_LOB);
$stmt->execute();

Displaying Database Images

Now that we have stored images in the database, we can display them on a web page. The typical approach to displaying images in PHP is to use the IMG tag with the SRC attribute pointing to the location of the image file. However, this approach will not work for database images because there is no physical file to point to. Instead, we need to output the image data directly to the browser. Here is an example PHP script that retrieves an image from the database and outputs it to the browser:

$id = 1; // ID of image to display

$stmt = $pdo->prepare("SELECT * FROM images WHERE id = :id");
$stmt->bindParam(':id', $id);
$stmt->execute();

$row = $stmt->fetch();

header("Content-type: image/jpeg");
echo $row['image'];

Make sure to set the Content-type header to the appropriate image type (e.g. image/jpeg, image/png) so that the browser knows how to display the image.

Conclusion

PHP provides a convenient way to store and display images in a database. However, displaying database images requires a different approach than displaying file system images. By understanding the concepts discussed in this article, you should be able to successfully display images stored in a database using PHP.