Php Wordpress-从存储为blob数据的数据库中获取图像

我有一个表单上传到数据库，并将图像存储为blob。我无法让它们输出

上传代码：

$image =  strip_tags(file_get_contents($_FILES['image']['tmp_name']));
$image_name = strip_tags($_FILES['image']['name']);
$image_size = getimagesize($_FILES['image']['tmp_name']);
if($image_size == FALSE) {
    echo 'An image has not been uploaded';
} else {
$wpdb->insert( 
    $table, 
    array( 
        'title' => $title,
        'description' => $description,
        'brand' => $brand,
        'img_name' => $image_name,
        'img' => $image,
    )
); 

显示图像的代码：

$product_id = get_query_var('id');

$image = $wpdb->get_results( "SELECT * FROM  products WHERE id = $product_id");

header("Content-Type: image/jpeg");

echo '<img src="data:image/jpeg;base64,'.base64_decode($image[0]->img).'" />';

在get.php中使用以下命令

要使其正常工作，我需要做哪些更改？

您正在获取表中该产品id的所有信息，然后尝试将其显示为图像。您需要从结果数组访问图像或仅选择图像，例如，使用get_var而不是get_results，选择img而不是*：

顺便说一句，这会让您接受SQL注入，因此您确实应该使用$wpdb->prepare在查询中包含一个变量，例如

$image = $wpdb->get_var( 
    $wpdb->prepare("SELECT img FROM products  WHERE id = %d", $product_id)  
);

水滴大小限制

请注意，MYSQL中的BLOB限制为64kb。如果图像大于此值，则需要使用16MB的MEDIUMBLOB

将图像路径保存为BLOB，而不是直接保存在数据库中

一个更实际的解决方案是只保存路径

要做到这一点，您需要创建一个文件夹将图像上传到，例如，在下面的“我的代码”中，在web根目录中创建一个名为“myimages”的文件夹，并在数据库中创建一个新的VARCHAR或TEXT列，在下面的示例中创建一个名为“img_path”的文件夹

/* 1. Define the path to the folder where you will upload the images to, 
      Note, this is relative to your web root. */ 
define (MY_UPLOAD_DIR, "myimages/");

$imagefilename = basename( $_FILES['image']['name']);

/* 2. define the full path to upload the file to, including the file name */
$fulluploadpath = get_home_path(). MY_UPLOAD_DIR . $imagefilename;

$image_name = strip_tags($_FILES['image']['name']);
$image_size = getimagesize($_FILES['image']['tmp_name']);

/* 3. Do your validation checks here, e.g. */
if($image_size == FALSE) {
    echo 'The image was not uploaded';
} 
/* 4. if everything is ok, copy the temp file to your upload folder */
else if(move_uploaded_file($_FILES['image']['tmp_name'], $fulluploadpath )) {
    /* 5. if the file was moved successfully, update the database */
    $wpdb->insert( 
        $table, 
        array( 
            'title' => $title,
            'description' => $description,
            'brand' => $brand,
            'img_name' => $image_name,
            'img_path' => MY_UPLOAD_DIR . $imagefilename, /* save the path instead of the image */
        )
    ); 

} else {
    //Display an error if the upload failed
    echo "Sorry, there was a problem uploading your file.";
}

要从数据库检索图像并显示它，请执行以下操作：

$product_id = get_query_var('id');
/* query the database for the image path */
$imagepath = $wpdb->get_var( 
    $wpdb->prepare("SELECT img_path FROM products  WHERE id = %d", $product_id)  
);

/* 6. Display the image using the path. 
      Because the path we used is relative to the web root, we can use it directly 
      by prefixing it with `/` so it starts at the webroot */ 
if ($imagepath)
    echo '<img src="/'.$imagepath.'" />';

上面的代码未经测试，但基本思想是存在的。同样，如果一个同名的文件已经存在，它将不起作用，所以您可能需要考虑为该名称添加一个时间戳以使其具有唯一性。 参考：

---

什么不起作用？这没有告诉我们多少。您尝试调试了什么-图像是否没有返回，图像是否返回但没有正确显示，或者您是否从数据库中得到了任何结果？当我运行$wpdb->prepare选项时，我没有得到任何返回，但是如果我检查代码，我会从您的注释中得到第一个选项。如果我运行print\r$img，我会看到所有的图像数据。好的，我们将首先集中精力使其工作。你试过使用echo吗；要显示它？是$image=$wpdb->get\u varSELECT img FROM products，其中id=$product\u id；回响返回尝试headerContent类型时发生的情况：image/jpeg；echo$image；？另外，数据库中的列类型是什么，您上载的图像大小是多少？

$image = $wpdb->get_var( 
    $wpdb->prepare("SELECT img FROM products  WHERE id = %d", $product_id)  
);

/* 1. Define the path to the folder where you will upload the images to, 
      Note, this is relative to your web root. */ 
define (MY_UPLOAD_DIR, "myimages/");

$imagefilename = basename( $_FILES['image']['name']);

/* 2. define the full path to upload the file to, including the file name */
$fulluploadpath = get_home_path(). MY_UPLOAD_DIR . $imagefilename;

$image_name = strip_tags($_FILES['image']['name']);
$image_size = getimagesize($_FILES['image']['tmp_name']);

/* 3. Do your validation checks here, e.g. */
if($image_size == FALSE) {
    echo 'The image was not uploaded';
} 
/* 4. if everything is ok, copy the temp file to your upload folder */
else if(move_uploaded_file($_FILES['image']['tmp_name'], $fulluploadpath )) {
    /* 5. if the file was moved successfully, update the database */
    $wpdb->insert( 
        $table, 
        array( 
            'title' => $title,
            'description' => $description,
            'brand' => $brand,
            'img_name' => $image_name,
            'img_path' => MY_UPLOAD_DIR . $imagefilename, /* save the path instead of the image */
        )
    ); 

} else {
    //Display an error if the upload failed
    echo "Sorry, there was a problem uploading your file.";
}

$product_id = get_query_var('id');
/* query the database for the image path */
$imagepath = $wpdb->get_var( 
    $wpdb->prepare("SELECT img_path FROM products  WHERE id = %d", $product_id)  
);

/* 6. Display the image using the path. 
      Because the path we used is relative to the web root, we can use it directly 
      by prefixing it with `/` so it starts at the webroot */ 
if ($imagepath)
    echo '<img src="/'.$imagepath.'" />';