import bulk images to wordpress - php

Question

I am migrating a very big website to wordpress.
I have about 35,000 images that I need to migrate to the wordpress environment from a custom cms made in native php.
I have uploaded the files via ftp to the wp-content directory but the wordpress media does not seem to recognize it, since it's missing the meta data in the mysql database.
I found the "add from server" plugin, but that plugin is limited to manually selecting images but when I select many images at once, it crashes.
Are there any other solution out there?

Answer 1

Use RecursiveDirectoryIterator in conjunction with RecursiveIteratorIterator. Then use wp_insert_attachment to add them to the WordPress database.
Note: I was not able to test this, but this is the general concept.
// Get WP uploads dir
$wp_upload_dir = wp_upload_dir();
// Init recursive Obj
$di = new RecursiveDirectoryIterator($wp_upload_dir['path']);
foreach (new RecursiveIteratorIterator($di) as $filename => $file) {
// get filetype for attachment meta
$filetype = wp_check_filetype( $file->getPathname(), null );
// attachment meta
$attachment = array(
'guid' => $wp_upload_dir['url'] . '/' . $filename,
'post_mime_type' => $filetype['type'],
'post_title' => preg_replace( '/\.[^.]+$/', '', $filename ),
'post_content' => '',
'post_status' => 'inherit'
);
// Insert the attachment.
$attach_id = wp_insert_attachment( $attachment, $filename );
}

Answer 2

When I was migrating a site with more than 55345 articles with images, I wrote some pure PHP scripts that perform migration, and then inserted images as follows (based on the explanation given by jackreichert):
$uploads = wp_upload_dir();
$save_path = $uploads['basedir'].'/importecms/'.$new_filename;
$attach_id = wp_insert_attachment( $artdata, $save_path, $post_id );
if ($attach_data = wp_generate_attachment_metadata( $attach_id, $save_path)) {
wp_update_attachment_metadata($attach_id, $attach_data);
}
$rows_affected = $wpdb->insert($wpdb->prefix.'postmeta', array('post_id' => $post_id, 'meta_key' => '_thumbnail_id', 'meta_value' => $attach_id));