Multiquery adapter for MySQLi database driver

multiquery.php

<?php

class MySQLi_Database extends Database {

...


  public function multiquery($sql)
  {
    // Make sure the database is connected
    $this->_connection or $this->connect();

    if (Kohana::$profiling)
    {
      // Benchmark this query for the current instance
      $benchmark = Profiler::start("Database ({$this->_instance})", $sql);
    }

    $result = mysqli_multi_query($this->_connection, $sql);

    // Execute the query
    if ($result === FALSE)
    {
      if (isset($benchmark))
      {
        // This benchmark is worthless
        Profiler::delete($benchmark);
      }

      throw new Database_Exception(':error [ :query ]',
        array(':error' => mysqli_error($this->_connection), ':query' => $sql),
        mysqli_errno($this->_connection));
    }

    if (isset($benchmark))
    {
      Profiler::stop($benchmark);
    }

    // Set the last query
    $this->last_query = $sql;

    $output = [];

    do
    {
      if ($result = mysqli_store_result($this->_connection))
      {
        while ($row = mysqli_fetch_row($result))
        {
          $output[] = $row[0];
        }

        mysqli_free_result($result);
      }

      if (mysqli_next_result($this->_connection))
        $output[] = 'multiquery done.';

    }

    while (mysqli_more_results($this->_connection));

    // return affected rows
    return implode("\n", $output);
  }

...

}