$and operator behavior in MongoDB - Mini Project: Build & Apply

$and Operator Behavior in MongoDB Queries

📖 Scenario: You are managing a small online bookstore database. You want to find books that meet multiple conditions at the same time, such as books that are both in stock and have a rating above a certain value.

🎯 Goal: Build a MongoDB query using the $and operator to find books that satisfy multiple conditions simultaneously.

📋 What You'll Learn

Create a collection named books with specific book documents.

Define a query filter using the $and operator with two conditions.

Use the find() method with the $and operator to retrieve matching documents.

Complete the query to return only books that are in stock and have a rating greater than 4.

💡 Why This Matters

🌍 Real World

In real online stores or libraries, you often need to find items that meet several conditions, like availability and quality ratings, to show to customers.

💼 Career

Understanding how to use the <code>$and</code> operator in MongoDB queries is essential for database developers and data analysts to filter data accurately.

1

Create the books collection with sample documents

Create a variable called books that contains an array of three book documents with these exact fields and values: { title: "Book A", inStock: true, rating: 4.5 }, { title: "Book B", inStock: false, rating: 4.7 }, and { title: "Book C", inStock: true, rating: 3.9 }.

MongoDB

# Create the books array with three book documents
# Your code here

Need a hint?

Use an array of objects with the exact field names and values given.

2

Define the $and query filter

Create a variable called query that uses the $and operator with two conditions: { inStock: true } and { rating: { $gt: 4 } }.

MongoDB

books = [
    { title: "Book A", inStock: true, rating: 4.5 },
    { title: "Book B", inStock: false, rating: 4.7 },
    { title: "Book C", inStock: true, rating: 3.9 }
]
# Define the query variable using $and with two conditions
# Your code here

Need a hint?

Use an object with $and as the key and an array of conditions as the value.

3

Write the find() query using the $and filter

Write a line that calls db.books.find(query) to find all books matching the query variable.

MongoDB

books = [
    { title: "Book A", inStock: true, rating: 4.5 },
    { title: "Book B", inStock: false, rating: 4.7 },
    { title: "Book C", inStock: true, rating: 3.9 }
]

query = { $and: [ { inStock: true }, { rating: { $gt: 4 } } ] }
# Use db.books.find(query) to get matching books
# Your code here

Need a hint?

Use the find() method on db.books with the query variable.

4

Complete the query to return only matching books

Assign the result of db.books.find(query) to a variable called result to complete the query operation.

MongoDB

books = [
    { title: "Book A", inStock: true, rating: 4.5 },
    { title: "Book B", inStock: false, rating: 4.7 },
    { title: "Book C", inStock: true, rating: 3.9 }
]

query = { $and: [ { inStock: true }, { rating: { $gt: 4 } } ] }

result = db.books.find(query)
# Your code here

Need a hint?

Make sure the query result is stored in result for further use.