src/CI_Base_Model.php
public function update_many($primary_values, $data)
    {
        $data = $this->_do_pre_update($data);

        if ($data !== FALSE)
        {
            $result = $this->_database->where_in($this->primary_key, $primary_values)
                ->set($data)
                ->update($this->_table);

            $this->trigger('after_update', array($data, $result));

            return $result;
        }

        return FALSE;
    }
public function update_many($primary_values, $data)
    {
        $data = $this->_do_pre_update($data);

        if ($data !== FALSE)
        {
            $result = $this->_database->where_in($this->primary_key, $primary_values)
                ->set($data)
                ->update($this->_table);

            $this->trigger('after_update', array($data, $result));

            return $result;
        }

        return FALSE;
    }
Update many records, based on an array of primary values.
@param $primary_values
@param $data
@return bool