Query Exact Matches in MongoDB - mongodb

Question

I am working on developing a web application feature that suggests prices for users based on previous orders in the database. I am using the MongoDB NoSQL database. Before I begin, I am trying to figure out the best way to set up the order object to return the correct results.
When a user places an order such as the following: 1 cheeseburger + 1 fry, McDonalds, 12345 E. Street, MyTown, USA... it should only return objects that are EXACT matches from the database.
For example, I would not want to receive an order that contained 1 cheeseburger + 1 fry + 1 shake. I will be keeping running averages of the prices and counts for that exact order.
{
restaurantAddress: "12345 E. Street, MyTown, USA",
restaurantName: "McDonald's",
orders: {
{ cheeseburger: 1, fries: 2 }
: {
sumPaid: 1444.55,
numTimesOrdered: 167,
avgPaid: 8.65 (gets recomputed w/ each new order)
},
{ // repeat for each unique item config },
{ // another unique item (or items) }
}
Do you think this is a valid and efficient way to set up the document in MongoDB? Or should I be using multiple documents?
If this is valid, how can I query it to only return exact orders? I looked into $eq but it did not seem to be exactly what I was looking for.

Answer 1

So I believe we have solved the problem. The solution is to create a string that is unique for the order on the server side. For example, we will write a function that would transform the 1 cheeseburger + 2 fries into burger1fries2. In order to keep consistency in the database, we will first sort the entries alphabetically, so we will always hit what we intended with the query. A similar order of 2 fries + 1 cheeseburger would generate the string burger1fries2 as well.