Import / Export bundle products using XAdapter Product Import Export for WooCommerce plugin - - with SKU

functions.php

add_filter('hf_insert_post_extra_data', 'hf_import_alter_product_csv_row_data', 100, 3);
add_action('hf_alter_product_export_csv_columns', 'hf_alter_product_csv_columns_head', 100);
add_action('hf_alter_product_export_csv_data', 'hf_alter_product_csv_row_data', 100, 2);

/**

  Product bundle export/import code snippet - with SKU
  @global type $wpdb
  @param type $additional_columns
  @return array
 */
function hf_alter_product_csv_columns_head($additional_columns) {
    global $wpdb;
    
    $table_name = $wpdb->prefix . 'woocommerce_bundled_itemmeta';
    $meta_keys = $wpdb->get_results($wpdb->prepare("SELECT DISTINCT * FROM $table_name ORDER BY `meta_key` ASC", array()));
    // get meta_key value from object
    $meta_keys = array_unique(wp_list_pluck($meta_keys, 'meta_key'));
    $additional_columns[] = 'meta:bundle_bundled_par_item_id';
    foreach ($meta_keys as $value) {
         if('real_id'!=$value){
         $additional_columns[] = 'meta:bundle_' . $value;         
         }                 
    }
    return $additional_columns;
}


function hf_alter_product_csv_row_data($additional_data, $productID) {
    global $wpdb;
    
    $bundled_items = $wpdb->get_results($wpdb->prepare('SELECT * FROM ' . $wpdb->prefix . 'woocommerce_bundled_items WHERE `bundle_id`=' . $productID, array()));
    $itemmeta = array();
    $par_id = '';
    foreach ($bundled_items as $key => $meta_value) {
        $prod = wc_get_product($meta_value->product_id);
        $par_id .= '|' . $prod->get_sku();
        $itemmeta[] = $wpdb->get_results($wpdb->prepare("SELECT * FROM " . $wpdb->prefix . "woocommerce_bundled_itemmeta WHERE `bundled_item_id`= $meta_value->bundled_item_id ORDER BY meta_key", array()));
    }
    $extra_data = array();
    if (is_array($itemmeta) && !empty($itemmeta)) {
        foreach ($itemmeta as $bundle_index => $bundled_arr) {
            if (is_array($bundled_arr) && !empty($bundled_arr)) {
                foreach ($bundled_arr as $key => $meta_value) {
                    if('real_id'!=$meta_value->meta_key){
                    isset($extra_data[$key]) ? $extra_data[$key] .= '|' . $meta_value->meta_value : $extra_data[$key] = $meta_value->meta_value;
                    }
                }
            }
        }
    }
    $additional_data[] = ltrim($par_id, '|');
    
    foreach ($extra_data as $key => $extra_value) {
        $additional_data[] = $extra_value;
    }
    
    return $additional_data;
}

function hf_import_alter_product_csv_row_data($post_meta, $post, $post_id = '') {    
    global $wpdb;
    foreach ($post_meta as $post_key => &$meta_array) {
        if ($meta_array['key'] == 'bundle_bundled_par_item_id') {
            $bundled_items_id = '';
            $bundle_par_id_arra = explode("|", $meta_array['value']); 
            foreach ($bundle_par_id_arra as $key => $sku) {
                $bundle_par_id_arra[$key] = wc_get_product_id_by_sku($sku);
            }
            $bundle_id = !empty($post_id) ? $post_id : $post['post_id'];
            foreach ($bundle_par_id_arra as $par_index => $bundle_par_id) {
                $results = $wpdb->get_results($wpdb->prepare('SELECT bundled_item_id FROM ' . $wpdb->prefix . 'woocommerce_bundled_items  WHERE `bundle_id`=' . $bundle_id . ' and `product_id`=' . $bundle_par_id, array()));                
                if (!$results) {
                    $wpdb->insert($wpdb->prefix . 'woocommerce_bundled_items', array('product_id' => $bundle_par_id, 'bundle_id' => !empty($post_id) ? $post_id : $post['post_id'],));
                    $bundled_items_id[$par_index] = $wpdb->insert_id;
                } else {
                    foreach ($results as $value) {
                        $bundled_items_id[$par_index] = $value->bundled_item_id;
                    }
                }
            }            
            unset($post_meta[$post_key]);
            continue;
        }

        if (!empty($bundled_items_id) && strpos($meta_array['key'], 'bundle_') !== false) {
            $meta_array['key'] = str_replace("bundle_", "", $meta_array['key']);
            $bundle_par_data_arra = explode("|", $meta_array['value']);
            $bundle_id = !empty($post_id) ? $post_id : $post['post_id'];            
            foreach ($bundle_par_data_arra as $par_index => $bundle_meta) {                                
                $results = $wpdb->get_results($wpdb->prepare('SELECT meta_id FROM ' . $wpdb->prefix . 'woocommerce_bundled_itemmeta  WHERE `bundled_item_id`=' . $bundled_items_id[$par_index] . ' and `meta_key`="'. $meta_array["key"].'"', array()));
                if (!$results) {                    
                    $wpdb->insert($wpdb->prefix . 'woocommerce_bundled_itemmeta', array('bundled_item_id' => $bundled_items_id[$par_index], 'meta_key' => $meta_array['key'], 'meta_value' => $bundle_meta,));                    
                } else {                   
                    $wpdb->update($wpdb->prefix . 'woocommerce_bundled_itemmeta', array('bundled_item_id' => $bundled_items_id[$par_index], 'meta_key' => $meta_array['key'], 'meta_value' => $bundle_meta,), array('meta_id'=>$results[0]->meta_id));                    
                }
            }
            unset($post_meta[$post_key]);
        }
    }
    return $post_meta;
}