Cakephp using bindmodel to get to deep relations

http://mark-story.com/posts/view/using-bindmodel-to-get-to-deep-relations

Now we want to find the Division that a particular Item belongs to. In normal SQL we could do

SELECT Division.id FROM items AS Item
LEFT JOIN categories AS Category ON Category.id = Item.category_id
LEFT JOIN sections AS SECTION ON SECTION.id = Category.section_id
LEFT JOIN divisions AS Division ON Division.id = SECTION.divison_id
WHERE Item.id = $id

And everything will happen in one query. In CakePHP we could use Containable to get at these deep relations. With a find call like

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$this->find('first', array(
    'conditions' => array('Item.id' => $itemId),
    'contain' => array('Category' => array('Section' => array('Division')))
));

This will work just fine however, it will also do 3 queries, one per table. In order to get the optimal query and stay inside the realm of non query() function we can use some bindModel() trickery.

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$this->unbindModel(array(
    'belongsTo' => array('Category')
));
 
$this->bindModel(array(
    'hasOne' => array(
        'Category' => array(
            'foreignKey' => false,
            'conditions' => array('Category.id = Item.category_id')
        ),
        'Section' => array(
            'foreignKey' => false,
            'conditions' => array('Section.id = Category.section_id')
        )
        'Division' => array(
            'foreignKey' => false,
            'conditions' => array('Division.id = Section.division_id')
        )
    )
));
$result = $this->find('first', array(
    'conditions' => array('Item.id' => $id),
    'contain' => array('Category', 'Section', 'Division'),
    'fields' => array('Division.id')
));

The above although much longer will create only one query. This will provide the fastest result performance wise.

منتشر شده در:Cakephp

تگ شده در:bindmodel

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Cakephp using bindmodel to get to deep relations

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