BulkSaveTrait.php

<?php

/**
 * Trait mixed into BAOs who support bulk-save operations
 */
trait CRM_Core_BulkSaveTrait {

  /**
   * @param $params
   * @return CRM_Core_DAO|NULL
   */
  public static function create($params) {
    $baoName = static::class;
    $method = empty($params['id']) ? '_bulkCreateObjects' : '_bulkUpdateObjects';
    $result = self::$method($baoName, [$params]);
    $obj = NULL;
    if (!empty($result[0])) {
      $obj = new static();
      $obj->copyValues($result[0]);
    }
    return $obj;
  }

  /**
   * @param $items
   * @param array $defaults
   * @param bool $reload
   * @return array[]
   */
  public static function bulkSave($items, $defaults = [], $reload = FALSE) {
    return self::_bulkSaveObjects(static::class, $items, $defaults);
  }

  /**
   * @param CRM_Core_DAO|string $baoName
   * @param array $items
   * @param array $defaults
   * @param bool $reload
   * @return array[]
   */
  public static function _bulkSaveObjects($baoName, $items, $defaults = [], $reload = FALSE) {
    $toCreate = $toUpdate = $result = [];
    foreach ($items as $item) {
      if (empty($item['id'])) {
        $toCreate[] = $item + (array) $defaults;
      }
      else {
        $toUpdate[$item['id']] = $item + (array) $defaults;
      }
    }
    if ($toCreate) {
      $result = self::_bulkCreateObjects($baoName, $toCreate);
    }
    if ($toUpdate) {
      $result = array_merge($result, self::_bulkUpdateObjects($baoName, $toUpdate, $reload));
    }
    return $result;
  }

  /**
   * @param CRM_Core_DAO|string $baoName
   * @param array $items
   * @return array[]
   */
  public static function _bulkCreateObjects($baoName, $items) {
    $fields = $baoName::fields();
    $result = [];

    // TODO:
    // - Call pre hooks for each item
    // - Compose efficient INSERT query & execute
    // - Save custom data
    // - Call post hooks

    return $result;
  }

  /**
   * @param CRM_Core_DAO|string $baoName
   * @param array $items
   * @param bool $reload
   * @return array[]
   */
  public static function _bulkUpdateObjects($baoName, $items, $reload) {

    // TODO: I don't think there IS a way to do a mass-update in mySql so I guess we'll just
    // - Loop through items, foreach:
    // - Call pre-hook
    // - Do a SQL UPDATE
    // - Save custom data
    // - Call post-hook
  }

}

See https://lab.civicrm.org/dev/core/issues/1093