fix-duplicated-entry-meta.php

<?php

add_action('admin_init', 'fix_duplicated_post_meta');

function fix_duplicated_post_meta()
{

    if (!isset($_GET['fix-divi-duplicated-post-meta'])) return;

    $post_meta = '_et_pb_use_builder';

    // select posts with duplicated post meta
    global $wpdb;
    $query = "SELECT post_id, meta_key, meta_value, COUNT(*) c
    FROM $wpdb->postmeta
    WHERE meta_key = '$post_meta'
    GROUP BY post_id, meta_key, meta_value
    HAVING c > 1";
    $posts = $wpdb->get_results($query);

    // loop through posts and delete duplicated post meta
    foreach ($posts as $post) {
        $post_id = $post->post_id;
        $query = "SELECT * FROM $wpdb->postmeta WHERE post_id = $post_id AND meta_key = '$post_meta'";
        $postmetas = $wpdb->get_results($query);
        $postmeta_ids = array_map(function ($postmeta) {
            return $postmeta->meta_id;
        }, $postmetas);
        $postmeta_ids = array_slice($postmeta_ids, 1);
        $postmeta_ids = implode(',', $postmeta_ids);
        $query = "DELETE FROM $wpdb->postmeta WHERE meta_id IN ($postmeta_ids)";
        $wpdb->query($query);
    }

    //flush object cache
    wp_cache_flush();

    //admin alert message
    
    add_action('admin_notices', 'fix_duplicated_post_meta_notice');

    function fix_duplicated_post_meta_notice()
    {
        ?>
        <div class="notice notice-success is-dismissible">
            <p><?php _e('Duplicated post meta has been fixed, please remove the code.', 'sample-text-domain'); ?></p>
        </div>
        <?php
    }

}