Question 1

You manage a MongoDB collection called inventory that stores documents for a store's inventory. Each document has the fields item, category, and quantity. You want to ensure that an item is always present in the collection, even if it needs to be inserted. Specifically, if the item "notebook" in the "Stationery" category does not exist, it should be inserted with a quantity of 50. If it does exist, its quantity should be updated to 50. You plan to use the following command:

db.inventory.updateOne(

{ "item": "notebook", "category": "Stationery" },

{ $set: { "quantity": 50 } },

{ upsert: true }

)

What will happen after executing this command if there is no "notebook" item in the "Stationery" category in the inventory collection?

Options :

A : A new document will be inserted with only quantity: 50, as other fields (item and category) are not mentioned in the $set operator.

B : Nothing will happen because the $set operator only updates existing documents and cannot insert new ones.

C : A new document will be inserted with quantity: 50, but the item field will be set to null.

D : A new document will be inserted with item: "notebook", category: "Stationery", and quantity: 50.

Answer: D

Question 2

You are managing a MongoDB collection named orders, where each document represents an order. The documents contain the following fields:order_id (String): The unique identifier for the order.customer_name (String): The name of the customer who placed the order.total_amount (Number): The total amount of the order.status (String): The status of the order, which can be "pending," "shipped," or "delivered."items (Array of Strings): A list of items included in the order.You want to find all orders that meet the following criteria:The order has a total amount greater than $1000.The order status is either "pending" or "shipped."The order contains either "laptop" or "smartphone" in the list of items.Which of the following queries would return the correct documents?

Options :

A :

B :

C :

D :

Answer: D

Question 3

What is the best practice in using the $match operator?

Options :

A : It doesn't matter when we apply $match stage.

B : MongoDB does not have a $match stage.

C : The later in the pipeline, the better.

D : The earlier in the pipeline, the better. Not only because we will be using expression filters which reduce the number of documents to be processed, but also because we can use indexes.

Answer: D

Question 4

Which of the following constraints might impact your data model for MongoDB? (Select three)

Options :

A : Operating System

B : RAM

C : Network

D : File System Type

E : Security & Compliance

Answer: B,C,E

Question 5

In a MongoDB collection named orders, you are tasked with retrieving a subset of documents that fulfill specific criteria. Each document in this collection contains the following fields: customerId, orderId, orderDate, and orderDetails (an embedded document with fields: product, quantity, unitPrice). You are required to fetch all orders made by the customer with a customerId of 1234 on a specific date 2023-04-12, and only return the orderId, orderDate, and product from orderDetails. Which of the following MongoDB queries would accurately fulfill these requirements?

Options :

A :

B :

C :

D :

Answer: A

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