Get attachment ID by file path in WordPress

问题:

I know the path of the file and I like to get the attachment ID.

There's a function wp_get_attachment_url() which requires the ID to get the URL but I need it reverse (with path not URL though)

回答1:

I used this cool snipped by pippinsplugins.com

Add this function in your functions.php file

// retrieves the attachment ID from the file URL
function pippin_get_image_id($image_url) {
    global $wpdb;
    $attachment = $wpdb->get_col($wpdb->prepare("SELECT ID FROM $wpdb->posts WHERE guid='%s';", $image_url )); 
        return $attachment[0]; 
}

Then use this code in your page or template to store / print / use the ID:

// set the image url
$image_url = 'http://yoursite.com/wp-content/uploads/2011/02/14/image_name.jpg';

// store the image ID in a var
$image_id = pippin_get_image_id($image_url);

// print the id
echo $image_id;

Original post here: https://pippinsplugins.com/retrieve-attachment-id-from-image-url/

Hope ti helps ;) Francesco

回答2:

UPDATE: since wp 4.0.0 there's a new function that could do the job. I didn't tested it yet, but it's this:

https://developer.wordpress.org/reference/functions/attachment_url_to_postid/

---

Late answer: so far, the best solution I've found out there, is the following:

http://frankiejarrett.com/get-an-attachment-id-by-url-in-wordpress/

I think It's the best for 2 reasons:

• It does some integrity checks
• [important!] it's domain-agnostic. This makes for safe site moving. To me, this is a key feature.

回答3:

Cropped URLs

None of the previous answers supported ID lookup on attachment URLs that contain a crop.

e.g: /uploads/2018/02/my-image-300x250.jpg v.s. /uploads/2018/02/my-image.jpg

Solution

Micah at WP Scholar wrote a blog post and uploaded the code to this Gist. It handles both original and cropped URL lookup.

I included the code below as a reference but, if you find useful, I'd encourage you to leave a comment on his post or star the gist.

/**
 * Get an attachment ID given a URL.
 * 
 * @param string $url
 *
 * @return int Attachment ID on success, 0 on failure
 */
function get_attachment_id( $url ) {

    $attachment_id = 0;

    $dir = wp_upload_dir();

    if ( false !== strpos( $url, $dir['baseurl'] . '/' ) ) { // Is URL in uploads directory?

        $file = basename( $url );

        $query_args = array(
            'post_type'   => 'attachment',
            'post_status' => 'inherit',
            'fields'      => 'ids',
            'meta_query'  => array(
                array(
                    'value'   => $file,
                    'compare' => 'LIKE',
                    'key'     => '_wp_attachment_metadata',
                ),
            )
        );

        $query = new WP_Query( $query_args );

        if ( $query->have_posts() ) {

            foreach ( $query->posts as $post_id ) {

                $meta = wp_get_attachment_metadata( $post_id );

                $original_file       = basename( $meta['file'] );
                $cropped_image_files = wp_list_pluck( $meta['sizes'], 'file' );

                if ( $original_file === $file || in_array( $file, $cropped_image_files ) ) {
                    $attachment_id = $post_id;
                    break;
                }

            }

        }

    }

    return $attachment_id;
}

Another pro with this solution is that we leverage the WP_Query class instead of making a direct SQL query to DB.

回答4:

Try attachment_url_to_postid function.

$rm_image_id = attachment_url_to_postid( 'http://example.com/wp-content/uploads/2016/05/castle-old.jpg' );
echo $rm_image_id;

More details

回答5:

Based on the answer from @FrancescoCarlucci I could do some improvements.

Sometimes, for example when you edit an image in WordPress, it creates a copy from the original and adds the copys upload path as post meta (key _wp_attached_file) which is not respected by the answer.

Here the refined query that includes these edits:

function jfw_get_image_id($file_url) {
    $file_path = ltrim(str_replace(wp_upload_dir()['baseurl'], '', $file_url), '/');

    global $wpdb;
    $statement = $wpdb->prepare("SELECT `ID` FROM `wp_posts` AS posts JOIN `wp_postmeta` AS meta on meta.`post_id`=posts.`ID` WHERE posts.`guid`='%s' OR (meta.`meta_key`='_wp_attached_file' AND meta.`meta_value` LIKE '%%%s');",
        $file_url,
        $file_path);

    $attachment = $wpdb->get_col($statement);

    if (count($attachment) < 1) {
        return false;
    }

    return $attachment[0]; 
}