Prisma ORM with GraphQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the resolver code to fetch all users using Prisma.

GraphQL

const resolvers = { Query: { users: async () => await prisma.user.[1]() } };

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

AgetAll

BfindMany

ClistUsers

DfetchAll

Attempts:

3 left

💡 Hint

Common Mistakes

Using methods like getAll or fetchAll which are not Prisma methods.

Trying to use listUsers which is not a Prisma client method.

The Prisma client uses findMany to fetch multiple records. So prisma.user.findMany is the correct method.

2fill in blank

medium

Complete the resolver code to fetch all posts using Prisma client.

GraphQL

const resolvers = { Query: { posts: async () => await prisma.post.[1]() } };

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

AfindMany

Bfetch

Clist

DgetAll

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent methods like getAll or fetch.

Confusing with list which is not a Prisma method.

To fetch multiple records in Prisma, use findMany(). Other options are not valid Prisma methods.

3fill in blank

hard

Fix the error in the mutation to create a new user with Prisma.

GraphQL

mutation { createUser(data: { name: "Alice", email: "[e-mail]" }) { [1] } }

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

Aid name email

Bcreate

Cuser

Ddata

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to put 'create' or 'data' which are not valid field selections.

Using 'user' which is not a field but a type.

In GraphQL mutations, after calling the mutation, you specify the fields you want returned. Here, id name email are the fields to return.

4fill in blank

hard

Fill both blanks to write a Prisma query that finds a unique user by email.

GraphQL

const user = await prisma.user.[1]({ where: { email: [2] } });

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

AfindUnique

B"[e-mail]"

CfindMany

Demail

Attempts:

3 left

💡 Hint

Common Mistakes

Using findMany which returns multiple records.

Not putting the email value in quotes.

findUnique is used to find a single record by a unique field. The email value must be a string, so it needs quotes.

5fill in blank

hard

Fill all three blanks to write a mutation that updates a user's name by id using Prisma.

GraphQL

const updatedUser = await prisma.user.[1]({ where: { id: [2] }, data: { name: [3] } });

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

Aupdate

B42

C"Bob"

Dcreate

Attempts:

3 left

💡 Hint

Common Mistakes

Using create instead of update.

Not quoting the name string.

Putting the id in quotes when it should be a number.

update is the Prisma method to update a record. The id is a number, and the new name is a string, so it needs quotes.

Practice

1. What is the main role of Prisma ORM when used with GraphQL?

easy

A. To define GraphQL schema types

B. To style the frontend user interface

C. To handle HTTP requests from clients

D. To manage database access and queries easily

Solution

1. Step 1: Understand Prisma ORM's purpose

   Prisma ORM acts as a tool to simplify database operations by providing an easy way to query and manage data.

2. Step 2: Differentiate Prisma from GraphQL schema and frontend roles

   GraphQL schema defines data types and operations, while frontend styling is unrelated to Prisma's role.

3. Final Answer:

   To manage database access and queries easily -> Option D

4. Quick Check:

   Prisma ORM = database access tool [OK]

Hint: Prisma handles database, GraphQL defines schema [OK]

Common Mistakes:

• Confusing Prisma with GraphQL schema definition
• Thinking Prisma manages frontend UI
• Assuming Prisma handles HTTP requests

2. Which of the following is the correct way to import Prisma Client in a Node.js GraphQL resolver file?

easy

A. import Prisma from 'prisma';

B. const PrismaClient = require('prisma-client');

C. import { PrismaClient } from '@prisma/client';

D. const { Prisma } = require('@prisma/client');

Solution

1. Step 1: Recall Prisma Client import syntax

   The official Prisma Client is imported using ES module syntax: import { PrismaClient } from '@prisma/client';

2. Step 2: Identify incorrect import forms

   Options B, C, and D use wrong package names or destructuring that Prisma does not support.

3. Final Answer:

   import { PrismaClient } from '@prisma/client'; -> Option C

4. Quick Check:

   Correct Prisma import = import { PrismaClient } from '@prisma/client'; [OK]

Hint: Use exact package '@prisma/client' with named import [OK]

Common Mistakes:

• Using wrong package name like 'prisma-client'
• Incorrect destructuring of PrismaClient
• Mixing CommonJS require with ES import incorrectly

3. Given this GraphQL resolver using Prisma:

const users = await prisma.user.findMany({ where: { active: true } });
return users;

What does this resolver return?

medium

A. All users including inactive ones

B. Only users with active set to true

C. An error because 'active' is not a valid field

D. An empty list always

Solution

1. Step 1: Analyze the Prisma query filter

   The query uses findMany with a where clause filtering users where active equals true.

2. Step 2: Understand the result of the query

   It returns only users whose active field is true, excluding inactive users.

3. Final Answer:

   Only users with active set to true -> Option B

4. Quick Check:

   findMany with where active:true = filtered users [OK]

Hint: Where filters results; active:true returns only active users [OK]

Common Mistakes:

• Assuming it returns all users ignoring filter
• Thinking it causes an error without schema check
• Believing it always returns empty list

4. You wrote this resolver code but get an error:

const newUser = prisma.user.create({
  data: {
    name: 'Alice'
  }
});
return newUser;

What is the likely cause of the error?

medium

A. Missing await before prisma.user.create call

B. Incorrect field name 'name' in data

C. Using create instead of findMany

D. Returning newUser before defining it

Solution

1. Step 1: Check asynchronous Prisma call

   prisma.user.create returns a Promise, so it needs await to resolve before returning.

2. Step 2: Identify missing await causing error

   Without await, newUser is a Promise, not the created user object, causing issues in return.

3. Final Answer:

   Missing await before prisma.user.create call -> Option A

4. Quick Check:

   Async Prisma calls need await [OK]

Hint: Always await Prisma async calls in resolvers [OK]

Common Mistakes:

• Forgetting to await async Prisma methods
• Assuming create returns data synchronously
• Confusing create with findMany usage

5. You want to fetch a user and their posts in one GraphQL query using Prisma. Which resolver code correctly fetches the user with their posts included?

hard

A. const user = await prisma.user.findUnique({ where: { id }, include: { posts: true } });

B. const user = await prisma.user.findMany({ where: { id }, select: { posts: false } });

C. const user = await prisma.post.findMany({ where: { userId: id } });

D. const user = await prisma.user.findUnique({ where: { id } }); const posts = await prisma.post.findMany({ where: { userId: id } });

Solution

1. Step 1: Understand Prisma's include option

   Using include: { posts: true } fetches related posts along with the user in one query.

2. Step 2: Compare options for fetching user with posts

   const user = await prisma.user.findUnique({ where: { id }, include: { posts: true } }); uses findUnique with include correctly; const user = await prisma.user.findMany({ where: { id }, select: { posts: false } }); excludes posts; const user = await prisma.post.findMany({ where: { userId: id } }); fetches posts only; const user = await prisma.user.findUnique({ where: { id } }); const posts = await prisma.post.findMany({ where: { userId: id } }); fetches separately, not in one query.

3. Final Answer:

   const user = await prisma.user.findUnique({ where: { id }, include: { posts: true } }); -> Option A

4. Quick Check:

   Include fetches relations in one query [OK]

Hint: Use include to fetch related data in one Prisma query [OK]

Common Mistakes:

• Using findMany instead of findUnique for single user
• Not using include to fetch related posts
• Fetching posts separately causing extra queries