Magento Read data from reviews table and display the json

Question

I want to create a module that read reviews data from database table in magento and display it in the form of json. How can i read data from database in magento?

Answer 1

To retrieve the review collection you can use \Magento\Review\Model\ResourceModel\Review\Product\Collection as unfortunately, as of now, Magento 2 does not provide a service layer for the Review module.

You can inject this class in your constructor:

protected $_productsFactory;
public function __construct(
 ...
 \Magento\Review\Model\ResourceModel\Review\Product\CollectionFactory $productsFactory,
 ...
) {
 ...
 $this->_productsFactory = $productsFactory;
 ...
}

Then you can call the following to get the collection:

$collection = $this->_productsFactory->create();

If you only want data for one product you can add:

$collection->addEntityFilter($productId);

Now to encode in JSON you need to inject the \Magento\Framework\Json\Helper\Data class in your constructor:

protected $_productsFactory;
protected $_jsonHelper;
public function __construct(
 ...
 \Magento\Review\Model\ResourceModel\Review\Product\CollectionFactory $productsFactory,
 \Magento\Framework\Json\Helper\Data $jsonHelper,
 ...
) {
 ...
 $this->_productsFactory = $productsFactory;
 $this->_jsonHelper = $jsonHelper;
 ...
}

Now in order to return a proper JSON I suggest you generate an array from the collection based on the data you need:

$result = [];
foreach ($collection as $review) {
 $result[] = ['title' => $review->getTitle(), 'nickname' => $review->getNickname(), 'detail' => $review->getDetail()];
}
$this->jsonHelper->jsonEncode($result);

• Rahul Agrawal: So u r saying that i cannot access the review_detail table to get the list of reviews??
• Raphael at Digital Pianism: @RahulAgrawal no that's not what I'm saying, what I posted will let you retrieve the list of reviews
• Raphael at Digital Pianism: @RahulAgrawal I'm saying that you will have to use the model factory instead of the service contracts
• Rahul Agrawal: from where do i call the collection part
• Rahul Agrawal: and i want the review of all the products