一次典型的查询

    public function product($media_ad_id = 0, $product_id = 0)
    {
        $this->MediaAd->id = $media_ad_id;
        $media_ad          = $this->MediaAd->read();
        if (!$media_ad) {
            $this->redirect(array(
                'action' => 'nofound'
            ));
        }
　　　　//这段代码用于验证用户操作
        $this->loadModel('MerchantProduct');
        $this->loadModel('MerchantProductCategory');
        $this->loadModel('MerchantProductPicture');
　　　　//载入模型
        $this->MerchantProduct->recursive = -1;
　　//关闭关联关系
        $product                          = $this->MerchantProduct->find('first', array(
            'fields' => array(
                'MerchantProduct.id',
                'MerchantProduct.details',
                'MerchantProduct.product_name',
                'MerchantProduct.sell_price',
                'MerchantProductCategory.id',
                'MerchantProductCategory.name'
            ),
//　需要的字段
            'joins' => array(
                array(
                    'table' => 'merchants',
                    'alias' => 'Merchant',
                    'type' => 'inner',
                    'conditions' => array(
                        'Merchant.id = MerchantProduct.merchant_id'
                    )
                ),
//关联
                array(
                    'table' => 'merchant_product_categories',
                    'alias' => 'MerchantProductCategory',
                    'type' => 'inner',
                    'conditions' => array(
                        'MerchantProductCategory.id = MerchantProduct.cate_id'
                    )
                )
            ),
            'conditions' => array(
                'MerchantProduct.id' => $product_id,
                'MerchantProduct.active=1',
                'Merchant.user_id' => $media_ad['MediaAd']['user_id']
            )
//条件
        ));
        if (!$product) {
            $this->redirect(array(
                'action' => 'nofound'
            ));
        }
        // 图片
        $pic = $this->MerchantProductPicture->find('list', array(
            'conditions' => array(
                'MerchantProductPicture.product_id' => $product_id
            )
        ));
//单独获取这部分数据也是可以的哈、
        $this->set(compact('product', 'pic', 'media_ad_id', 'media_ad'));
//输出到页面
    }