MongoDB & PHP get only product that matches barcode - php

Question

I have this JSON and you can see under products i have barcodes for each product what i want to do is only get the information that matches the product barcode
{
"company": "village",
"logo": "http:\/\/www.incard.com.au\/newsite\/template\/images\/movieticket\/4cinemas\/villagetop.png",
"products": [
{
"barcode": "236690091",
"name": "Weekday",
"logo-URL": "http: \/\/www.incard.com.au\/newsite\/template\/images\/movieticket\/4cinemas\/ticketpic1.png",
"price": "12.50",
"discount": "1.50"
},
{
"barcode": "236690092",
"name": "Weekend",
"logo-URL": "http: \/\/www.incard.com.au\/newsite\/template\/images\/movieticket\/4cinemas\/ticketpic1.png",
"price": "13.50",
"discount": "1.60"
},
{
"barcode": "236690093",
"name": "Gold Class",
"logo-URL": "http: \/\/www.incard.com.au\/newsite\/template\/images\/movieticket\/4cinemas\/ticketpic1.png",
"price": "13.50",
"discount": "1.60"
}
],
"store_name": "movies"
}
for example If i hit 236690091 I only what the database (MongoDB) to return
"barcode": "236690091",
"name": "Weekday",
"logo-URL": "http: \/\/www.incard.com.au\/newsite\/template\/images\/movieticket\/4cinemas\/ticketpic1.png",
"price": "12.50",
"discount": "1.50"
not every product.
This is what I have tried
public function getbarcode($barcode)
{
// select a collection (analogous to a relational database's table)
$collection = $this->db->movies->products;
// find everything in the collection
$cursor = $collection->find(array("barcode" =>"{$barcode}"));
$test = array();
// iterate through the results
while( $cursor->hasNext() ) {
$test[] = ($cursor->getNext());
}
//Print Results
print json_encode($test);
}

Answer 1

You can't do this. MongoDB will always return the full document and will not allow you to return only a nested part that you want to search against. I would suggest to split out the products into its own collection, and then add the company info to each product. This will also circumvent the 16MB document limit in case you have lots of products for each company.
Without changing your schema, the following code should work:
public function getbarcode($barcode)
{
$products = array();
$collection = $this->db->movies->products;
foreach( $collection->find( array( 'products.barcode' => $barcode ) ) as $item )
{
foreach( $item->products as $product )
{
if ( $product['barcode'] == $barcode )
{
$products[] = $item;
}
}
}
return $products;
}

Answer 2

You can't do this the way you want. MongoDB will return only whole documents or some fields from the documents (if you specify them in query). You can't return only values that are matched by your query.
You can create a separate collection that will only hold the products objects (with a reference to a collection that holds the company data) where you can directly query for the product data you want.
If you can't / won't create another collection you can find all documents that have the product with specified barcode and filter them out using PHP.
For this second approach your query should be:
$collection->find(array("products.barcode" =>"{$barcode}"),
array('products' => 1));
With this query you're reaching into objects and returning only documents that have the barcode you are looking for.
Also, in this query you will only return the products property from your document and not the whole document. The products property will contain all the child objects, not just the one you are trying to find.
In your while loop you should check the values and filter them out properly.