MongoDB with GraphQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a GraphQL query that fetches all users from MongoDB.

GraphQL

type Query { users: [User] [1] }

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A!

C?

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Adding '!' which makes the list non-nullable and may cause errors if no users exist.

The users field returns a list of User objects. No exclamation mark means it can be null or empty.

2fill in blank

medium

Complete the resolver function to fetch all users from MongoDB collection.

GraphQL

const resolvers = { Query: { users: async () => await db.collection('[1]').find().toArray() } }

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

Acustomers

Busers

Corders

Dproducts

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong collection name like 'orders' or 'products' which returns wrong data.

The MongoDB collection name for users is usually 'users'.

3fill in blank

hard

Fix the error in the GraphQL schema for a User type with an ID field.

GraphQL

type User { id: [1] name: String }

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AInt

BID!

CString!

DBoolean

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Int' or 'Boolean' for ID which is not correct for unique identifiers.

The ID field should be of type 'ID!' to uniquely identify the user and be non-nullable.

4fill in blank

hard

Fill both blanks to define a mutation that adds a new user with a name argument.

GraphQL

type Mutation { addUser(name: [1]): User [2] }

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

AString!

BBoolean

C!

DID

Attempts:

3 left

💡 Hint

Common Mistakes

Leaving out '!' which allows null values and may cause errors.

The name argument should be a non-nullable String, and the mutation returns a User type with a non-nullable result.

5fill in blank

hard

Fill all three blanks to write a resolver for addUser mutation that inserts a user and returns it.

GraphQL

const resolvers = { Mutation: { addUser: async (_, { [1] }) => { const result = await db.collection('users').insertOne({ [2] }); return result.[3]; } } }

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

Aname

Bname: name

Cops[0]

DinsertedId

Attempts:

3 left

💡 Hint

Common Mistakes

Returning 'insertedId' instead of the full inserted document.

Not matching argument name and inserted document field.

The resolver takes 'name' argument, inserts a document with 'name: name', and returns the inserted document from 'ops[0]'.