test> db.orders.insertMany([
{ "item" : "almonds", "price" : 12, "quantity" : 2 },
{ "item" : "pecans", "price" : 20, "quantity" : 1 },
])
test> db.inventory.insertMany([
{ "sku" : "almonds", "description": "product 1", "instock" : 120 },
{ "sku" : "cashews", "description": "product 3", "instock" : 60 },
{ "sku" : "pecans", "description": "product 4", "instock" : 70 }
])
test> db.orders.aggregate([
{ $match: { price: { $lt: 15 } } },
{ $lookup: {
from: "inventory",
localField: "item",
foreignField: "sku",
as: "inventory_docs"
} },
{ $sort: { price: 1 } },
])