Zend和数据映射器-如何从多个表中获取数据

Question

I am newbie to Data Mappers concept and so far I only used Active Record.

I have following MySQL tables:

Calendar

• id
• idEvent
• date

Events

• id
• name

I need to fetch names and dates of all events that happened before today.

What's the most efficient structure to archive this? I am getting super confused if I need to create objects for each Calendar entry, and how will I link idEvent from calendar table and id from events table.

Answer 1

In yourProjectRootFolder/application/Module/models/mappers/CalendarMapper.php (amend the path as per your directory structure if you're not using the same):

<?php

class Module_Model_Mapper_Calendar extends Your_Abstract_Mapper
{
    public function rowToObject($row)
    {
        $calendar = new Module_Model_Calendar();
        $calendar->setDate($row->date);

        if(!empty($row->idEvent))
        {
            $eventMapper = new Module_Model_Mapper_Event();
            $event = $eventMapper->find($row->idEvent);
            $calendar->setEvent($event);
        }


        return $calendar;
    }

Now, each time you call $calendarMapper->find($calendarId); in your controller, you should be provided with both Calendar object with Event object linked to it.