NoSQL and alternative models in Intro to Computing - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to select all documents from a MongoDB collection named 'users'.

Intro to Computing

db.users.[1]()

Drag options to blanks, or click blank then click option'

Afind

Bselect

Cquery

Dget

Attempts:

3 left

💡 Hint

Common Mistakes

Using SQL-like commands such as 'select' instead of MongoDB methods.

Trying to use 'get' which is not a MongoDB collection method.

In MongoDB, the find() method retrieves all documents from a collection.

2fill in blank

medium

Complete the code to insert a document with name 'Alice' into the 'users' collection in MongoDB.

Intro to Computing

db.users.[1]({"name": "Alice"})

Drag options to blanks, or click blank then click option'

Aadd

BinsertOne

Cput

Dsave

Attempts:

3 left

💡 Hint

Common Mistakes

Using SQL commands like 'add' or 'save' which do not exist in MongoDB.

Confusing with bulk insert methods like 'insertMany'.

The insertOne() method inserts a single document into a MongoDB collection.

3fill in blank

hard

Fix the error in the MongoDB query to find users older than 25.

Intro to Computing

db.users.find({"age": {"[1]": 25}})

Drag options to blanks, or click blank then click option'

A=

B>

C$gt

D=>

Attempts:

3 left

💡 Hint

Common Mistakes

Using plain '>' which is invalid in MongoDB queries.

Using '=' which means exact match, not greater than.

MongoDB uses $gt to represent 'greater than' in queries.

4fill in blank

hard

Fill both blanks to create a key-value pair in a Redis command to set the key 'user:1' with value 'Alice'.

Intro to Computing

SET [1] [2]

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Auser:1

BAlice

Cuser1

DBob

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping key and value positions.

Using incorrect key names like 'user1' without colon.

Redis SET command syntax is SET key value. Here, key is 'user:1' and value is 'Alice'.

5fill in blank

hard

Fill all three blanks to create a Cassandra CQL query that selects all columns from the 'employees' table where 'department' equals 'sales'.

Intro to Computing

SELECT [1] FROM [2] WHERE [3] = 'sales';

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A*

Bemployees

Cdepartment

Demployee

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong table name like 'employee'.

Using wrong column name in WHERE clause.

In Cassandra CQL, SELECT * selects all columns, FROM employees specifies the table, and WHERE department = 'sales' filters rows.