PHP和MongoDB查询-获取文档中的通用值列表

Question

I'm currently working on an e-commerce solution of my own.

First, a product document look like that -

{
    "_id" : ObjectId("...."),
    "sku" : "",
    "manufacturer" : "", // Manufacturer
    "quantity" : 0,
    "price" : 0,
    "currency" : "", // Currency code
    "warranty" : "", // Yes/No/True/False
    "installation" : "", // Installiton type/required
    "images" : [], // array of img paths
    "creation" : ISODate("...."),
    "lastModified" : ISODate("...."),
    "details" : [], // array of object each for different language
    "properties" : [ 
        {
            "property" : "", // property name, unique
            "value" : "" // propery value
        }
    ],
    "customize" : [ 
        {
            "property" : "", // property name
            "type" : "", // input type: radio, select, etc.
            "options" : [ 
                {
                    "id" : 1, // numeric id
                    "option" : "", // option text
                    "cost" : 0.0 // option additional price
                }
            ]
        }
    ],
    "categories" : [], // array of objects {category:1, subs[2,3,4]}
    "excludes" : [],
    "shipping" : [], // array of objects {location:FR, price:5, additional: 1}
}

So, what I want to be able to do is to get a list of filters (max of 5, the most common).

Filters I need:

1. simple filters - all values available for manufacturer + count for each
2. nested filters - all values available for array_of_obj.x + count (example: properties.property)
3. even more nested for the customize array and categories array, but it will be just a bonus.

How can I achieve each one? Will it be too heavy?

In case the query will be too complex, will it be better to get all products to an array of products (I'm using setTypeMap in order to unserialize the data directly to my php class) and then play with array_column, foreach etc.?

Answer 1

Thanks to Neil Lunn, I managed to solve my problem by using $facet aggregation pipeline stage, even with the complex structure of an array => object => array .

I'll post my code with a full explanation soon, in order to help others here.