CRUD operations with Prisma in NextJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new user with Prisma.

NextJS

const newUser = await prisma.user.[1]({ data: { name: 'Alice', email: '[e-mail]' } });

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

Aupdate

BfindMany

Cdelete

Dcreate

Attempts:

3 left

💡 Hint

Common Mistakes

Using findMany instead of create

Using update when creating new data

The create method is used to add a new record in Prisma.

2fill in blank

medium

Complete the code to fetch all users from the database.

NextJS

const users = await prisma.user.[1]();

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

Acreate

BfindMany

Cdelete

Dupdate

Attempts:

3 left

💡 Hint

Common Mistakes

Using create instead of findMany

Using update when fetching data

The findMany method retrieves multiple records from the database.

3fill in blank

hard

Fix the error in the code to update a user's email by ID.

NextJS

const updatedUser = await prisma.user.update({ where: { id: [1] }, data: { email: '[e-mail]' } });

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

A123

B'123'

Cemail

DuserId

Attempts:

3 left

💡 Hint

Common Mistakes

Using string ID when schema expects number

Using wrong field name for ID

The id should be a number without quotes if the schema defines it as an integer.

4fill in blank

hard

Fill both blanks to delete a user by email.

NextJS

const deletedUser = await prisma.user.[1]({ where: { [2]: '[e-mail]' } });

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

Adelete

Bemail

Cid

Dupdate

Attempts:

3 left

💡 Hint

Common Mistakes

Using update instead of delete

Using id instead of email in where clause

Use delete to remove a record and specify the field email in the where clause.

5fill in blank

hard

Fill all three blanks to find a user by ID and update their name.

NextJS

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

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

Aupdate

Bid

C42

Demail

Attempts:

3 left

💡 Hint

Common Mistakes

Using findMany instead of update

Using email instead of id

Using string instead of number for ID

Use update method, specify id as the field, and provide the numeric ID 42.

Practice

1. What does the prisma.user.create() method do in Next.js with Prisma?

easy

A. It adds a new user record to the database.

B. It fetches all user records from the database.

C. It updates an existing user record.

D. It deletes a user record from the database.

Solution

1. Step 1: Understand the method name

   The method create() is used to add new data in Prisma.

2. Step 2: Match method to CRUD operation

   Creating means adding new records, so prisma.user.create() adds a new user.

3. Final Answer:

   It adds a new user record to the database. -> Option A

4. Quick Check:

   Create method = Add new record [OK]

Hint: Create method adds new data, not read or delete [OK]

Common Mistakes:

• Confusing create() with findMany() which reads data
• Thinking create() updates existing records
• Assuming create() deletes records

2. Which of the following is the correct syntax to update a user with id 5 using Prisma in Next.js?

easy

A. prisma.user.edit({ where: { id: 5 }, data: { name: 'Alice' } })

B. prisma.user.modify({ id: 5, name: 'Alice' })

C. prisma.user.update({ where: { id: 5 }, data: { name: 'Alice' } })

D. prisma.user.change({ id: 5, data: { name: 'Alice' } })

Solution

1. Step 1: Identify Prisma update syntax

   Prisma uses update() with where and data keys to update records.

2. Step 2: Check option correctness

   Only prisma.user.update({ where: { id: 5 }, data: { name: 'Alice' } }) uses correct method update() and proper keys where and data.

3. Final Answer:

   prisma.user.update({ where: { id: 5 }, data: { name: 'Alice' } }) -> Option C

4. Quick Check:

   Update method uses where and data keys [OK]

Hint: Update uses update({ where, data }) syntax [OK]

Common Mistakes:

• Using non-existent methods like modify(), change(), edit()
• Missing where or data keys in update()
• Passing id directly without where object

3. Given this code snippet in Next.js with Prisma:

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

What will console.log(users.length) output?

medium

A. Always 0, because findMany returns undefined.

B. The total number of users, active or not.

C. An error because findMany needs data key.

D. The number of active users in the database.

Solution

1. Step 1: Understand findMany with where filter

   The findMany() method returns an array of records matching the where condition.

2. Step 2: Analyze the filter condition

   Only users with active: true are returned, so users.length is count of active users.

3. Final Answer:

   The number of active users in the database. -> Option D

4. Quick Check:

   findMany with where returns filtered array [OK]

Hint: findMany returns array; length counts filtered records [OK]

Common Mistakes:

• Thinking findMany returns undefined or error
• Ignoring the where filter effect
• Assuming it returns all users without filter

4. Identify the error in this Prisma delete operation:

await prisma.user.delete({ id: 10 });

medium

A. Missing the 'where' key wrapping the id.

B. Using delete() instead of remove().

C. id should be a string, not a number.

D. delete() cannot be used with await.

Solution

1. Step 1: Check delete() method syntax

   Prisma's delete() requires an object with a where key specifying the record to delete.

2. Step 2: Identify missing where key

   The code passes { id: 10 } directly, missing where: { id: 10 }.

3. Final Answer:

   Missing the 'where' key wrapping the id. -> Option A

4. Quick Check:

   Delete needs where key with id [OK]

Hint: Delete needs where: { id } object, not just id [OK]

Common Mistakes:

• Omitting where key in delete()
• Using remove() which does not exist in Prisma
• Thinking id type must be string always
• Believing delete() can't be awaited

5. You want to update a user's email only if the user exists, otherwise create a new user with that email. Which Prisma method best fits this use case in Next.js?

hard

A. prisma.user.create({ data: { email } })

B. prisma.user.upsert({ where: { email }, update: { email }, create: { email } })

C. prisma.user.update({ where: { email }, data: { email } })

D. prisma.user.findUnique({ where: { email } })

Solution

1. Step 1: Understand the upsert method

   Upsert updates if record exists, else creates new one in Prisma.

2. Step 2: Match use case to method

   Since we want to update or create based on existence, upsert() fits perfectly.

3. Final Answer:

   prisma.user.upsert({ where: { email }, update: { email }, create: { email } }) -> Option B

4. Quick Check:

   Upsert = update or create [OK]

Hint: Use upsert to update or create in one call [OK]

Common Mistakes:

• Using update() alone which fails if user missing
• Using create() alone which fails if user exists
• Using findUnique() which only reads data