MongoDB Query Language: Beginner-Level Quiz

MongoDB Query Language Quiz

Welcome to the MongoDB Query Language quiz, a quiz designed to assess your understanding of the foundational concepts and best practices related to MongoDB, a powerful document-oriented NoSQL database. Let's get right at it!

1 / 20

How would you skip the first 5 documents in the query result?

db.collection.find().omit(5)

db.collection.find().jump(5)

db.collection.find().skip(5)

db.collection.find().ignore(5)

2 / 20

How would you sort query results in descending order based on the "name" field?

db.collection.find().sort({ name: -1 })

db.collection.find().orderBy({ name: -1 })

db.collection.find().sort({ name: 1 })

db.collection.find().sort({ name: desc })

3 / 20

Which MongoDB query is used to retrieve all documents from a collection?

db.collection.find()

db.collection.getAll()

db.collection.fetchAll()

db.collection.show()

4 / 20

What does the $all operator do when querying array fields?

Sorts the array elements in ascending order

Returns documents where the array contains all specified elements

Checks if the array field exists in the document

Returns documents where the array contains at least one matching element

5 / 20

What is the purpose of the aggregate() method in MongoDB?

To perform data aggregation operations, such as grouping and filtering

To create compound indexes

To execute multiple queries simultaneously

To merge multiple documents into one

6 / 20

Which MongoDB query would return documents where the "age" field is either 25 or 30?

{ age: { $eq: [25, 30] } }

{ age: { $or: [25, 30] } }

{ age: { $between: [25, 30] } }

{ age: { $in: [25, 30] } }

7 / 20

Which operator allows you to combine multiple conditions in a single query?

$in

$or

$merge

$and

8 / 20

Which operator is used to match documents where a field value is greater than a specified value?

$gte

$lte

$eq

$gt

9 / 20

What does the $inc operator do in MongoDB?

Decreases the value of a field by 1

Replaces a field value with a new one

Increments the value of a field by a specified amount

Inserts a new field if it doesn’t exist

10 / 20

Which operator allows you to query documents that contain an array field with a specific value?

$exists

$elemMatch

$set

$group

11 / 20

Which of the following is a key feature of MongoDB?

Predefined schemas and data constraints

Automatic SQL query optimization

Horizontal scaling through sharding

Native support for foreign keys

12 / 20

Which of the following queries uses the $or operator correctly?

{ $or: [ { field1: 'value1' }, { field2: 'value2' } ] }

{ $or: { field1: 'value1', field2: 'value2' } }

{ field1: 'value1' || field2: 'value2' }

{ $or: [ { field1: 'value1' }, { field2: 'value2' } ] }

13 / 20

How can you ensure that only distinct values are retrieved from a collection?

Using db.collection.find({ distinct: true })

Using the $unique operator

By creating a unique index

Using the distinct() method

14 / 20

What is the primary reason developers use MongoDB?

Support for large SQL queries

Automatic report generation

Strict schema enforcement

Flexible schema and scalability

15 / 20

What is the purpose of the $exists operator?

To filter documents with non-empty fields

To check if a field exists or not in a document

To create new fields dynamically

To delete documents without specific fields

16 / 20

How would you query documents where a field exists but is not null?

{ field: { $exists: true, $not: { $eq: null } } }

{ field: { $exists: true, $null: false } }

{ field: { $eq: !null } }

{ field: { $exists: true, $ne: null } }

17 / 20

What is the difference between $in and $nin operators?

$in matches documents containing specified values, and $nin matches documents that do not contain them

$in checks for numerical values, while $nin checks for non-numerical values

$nin is used for nested queries, while $in is not

$in is used for indexes, while $nin is used for aggregations

18 / 20

What does the $regex operator do in a MongoDB query?

Sorts the documents in ascending order

Joins two collections based on a pattern

Deletes documents with a matching field value

Matches documents where the field value satisfies a regular expression pattern

19 / 20

What does the $push operator do in MongoDB?

Appends a document to the collection

Adds a value to an array field

Removes a value from an array field

Sorts the elements of an array field

20 / 20

Which of the following best describes MongoDB?

In-memory key-value store

Document-oriented NoSQL database

Relational Database Management System

SQL-based data warehouse

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The average score is 0%

MongoDB Query Language (MQL) covers the syntax and functionality used to interact with and retrieve data from MongoDB.

The topic also explores how to sort, project, and limit query results, manage nested fields, and perform advanced operations such as joins using $lookup.

This quiz is designed for those with a basic understanding of MongoDB who want to deepen their skills in querying and manipulating data effectively for various application needs.