Query-2.js

# Suppliers collection
suppliersCollection = myDB["suppliers"]
fresh_product_details= suppliersCollection.aggregate([
       # search for the nearest stores within 2000m of the customers (C1) address
       # 'distanceFromYou' field was created to show the customer how far the store is from
them (in metres)
       {
       "$geoNear":{
       "near":{
               "type":"Point",
               "coordinates":[
               53.4702888668,
               -2.26459207339
               ]
       },
       "distanceField":"distanceFromYou",
       "maxDistance":2000
       }
},
       # Filter by all suppliers which are Morrisons (as only these stock the fresh
products)
{
"$match":{
       "name":{
               '$regex' : '.*' + 'Morrisons' + '.*'
}
} },
       # Inventory data for products is in an array of embedded documents so we need to
unwind
   {
       "$unwind":"$realtime_inventory"
},
{
"$match":{
       "realtime_inventory.quantity":{
               "$gte":1
}
} },
# Filter for all quantities greater or equal to 1 (indicating its available)
         # Get the products collection using $lookup
   {
       "$lookup":{
       "from":"products",
       "localField":"realtime_inventory.product_id",
       "foreignField":"_id",
       "as":"availableProducts"
       }
}, {
       "$unwind":"$availableProducts"
   },
       # Sort the documents using 'distanceFromYou', to show closest stores first
{
"$sort":{
       "distanceFromYou":1
} },
       # Group the items back together on supplier id. availableProducts field is created
which holds info
       # from products collection
{
"$group":{
"_id":"$_id",
'name' : { '$first': '$name' },
'address' : { '$first': '$address' },
# Outputting the distance from the customer and rounding it to 2 decimal places 'distanceFromYou' : { '$first': {'$round': [ '$distanceFromYou', 2 ] }} ,
       "availableProducts":{
               "$push":"$availableProducts"
}
} },
       # Project (display) the useful fields to the customer
   {
       "$project":{
       "name":1,
       "address":1,
       "distanceFromYou":1,
       "availableProducts._id":1,
       "availableProducts.name":1,
       "availableProducts.short_desc":1,
       "availableProducts.dimensions":1,
       "availableProducts.avg_ratings":1,
       "availableProducts.std_price":1
       }
} ])

for i in fresh_product_details:
       pprint.pprint(i)