CRUD with Prisma in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new user using Prisma client.

NestJS

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

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

Acreate

BfindUnique

Cupdate

Ddelete

Attempts:

3 left

💡 Hint

Common Mistakes

Using findUnique instead of create will only search, not add data.

Using update or delete will modify or remove data, not create.

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

2fill in blank

medium

Complete the code to find a user by their unique email.

NestJS

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

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

Acreate

BfindUnique

Cdelete

Dupdate

Attempts:

3 left

💡 Hint

Common Mistakes

Using create will add a new user instead of finding one.

Using update or delete will modify or remove data, not fetch.

The findUnique method fetches a single record by a unique field like email.

3fill in blank

hard

Fix the error in updating a user's name by their ID.

NestJS

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

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

Acreate

BfindUnique

Cupdate

Ddelete

Attempts:

3 left

💡 Hint

Common Mistakes

Using create will add a new user instead of updating.

Using findUnique only fetches data, does not update.

Using delete removes data instead of updating.

The update method changes existing records based on a unique identifier.

4fill in blank

hard

Fill both blanks to delete a user by their ID and return the deleted user.

NestJS

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

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

Adelete

Bupdate

CuserId

Dcreate

Attempts:

3 left

💡 Hint

Common Mistakes

Using update or create will not delete the user.

Passing a wrong variable name instead of userId causes errors.

The delete method removes a record by unique criteria, here by userId.

5fill in blank

hard

Fill all three blanks to update a user's email by their ID and return the updated user.

NestJS

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

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

Acreate

BuserId

C'[e-mail]'

Dupdate

Attempts:

3 left

💡 Hint

Common Mistakes

Using create instead of update adds a new user.

Forgetting quotes around the new email string causes syntax errors.

Using wrong variable names for ID causes runtime errors.

Use update to change the email of a user identified by userId with the new email string.

Practice

1. In NestJS with Prisma, which method is used to retrieve multiple records from the database?

easy

A. create

B. update

C. findMany

D. delete

Solution

1. Step 1: Understand Prisma CRUD methods

   Prisma provides create to add, findMany to get multiple records, update to change, and delete to remove records.

2. Step 2: Identify method for retrieving multiple records

   The method findMany is specifically designed to fetch many records from the database.

3. Final Answer:

   findMany -> Option C

4. Quick Check:

   Retrieve multiple records = findMany [OK]

Hint: Remember: findMany fetches many records [OK]

Common Mistakes:

• Confusing create with findMany
• Using update to retrieve data
• Trying to delete to get records

2. Which of the following is the correct syntax to create a new user record using Prisma in a NestJS service?

easy

A. this.prisma.user.create({ data: { name: 'Alice' } })

B. this.prisma.user.findMany({ data: { name: 'Alice' } })

C. this.prisma.user.update({ data: { name: 'Alice' } })

D. this.prisma.user.delete({ data: { name: 'Alice' } })

Solution

1. Step 1: Identify the method to add a record

   The create method is used to add new records in Prisma.

2. Step 2: Check the syntax for creating a user

   The correct syntax is this.prisma.user.create({ data: { ... } }) where data holds the new record's fields.

3. Final Answer:

   this.prisma.user.create({ data: { name: 'Alice' } }) -> Option A

4. Quick Check:

   Create new record = create method [OK]

Hint: Use create with data object to add records [OK]

Common Mistakes:

• Using findMany instead of create
• Passing data to update without where clause
• Using delete method to add records

3. Given this Prisma update call in a NestJS service:

this.prisma.user.update({ where: { id: 5 }, data: { email: '[e-mail]' } })

What will this operation do?

medium

A. Delete the user with id 5

B. Update the email of the user with id 5 to '[e-mail]'

C. Create a new user with id 5 and email '[e-mail]'

D. Return all users with email '[e-mail]'

Solution

1. Step 1: Understand the update method parameters

   The update method requires a where clause to find the record and data to specify changes.

2. Step 2: Analyze the given call

   It targets user with id: 5 and changes the email field to '[e-mail]'.

3. Final Answer:

   Update the email of the user with id 5 to '[e-mail]' -> Option B

4. Quick Check:

   Update with where and data changes record [OK]

Hint: Update needs where to find record, data to change [OK]

Common Mistakes:

• Thinking update creates new records
• Confusing update with delete
• Missing where clause causes errors

4. What is wrong with this Prisma delete call in a NestJS service?

this.prisma.user.delete({ data: { id: 3 } })

medium

A. The delete method should use a where clause, not data

B. The delete method cannot delete by id

C. The syntax is correct and will delete user with id 3

D. The delete method requires an update object

Solution

1. Step 1: Check Prisma delete method syntax

   The delete method requires a where clause to specify which record to remove.

2. Step 2: Identify the error in the code

   The code incorrectly uses data instead of where, causing a syntax error.

3. Final Answer:

   The delete method should use a where clause, not data -> Option A

4. Quick Check:

   Delete needs where, not data [OK]

Hint: Delete uses where to find record, not data [OK]

Common Mistakes:

• Using data instead of where in delete
• Trying to update in delete method
• Omitting where clause causes errors

5. You want to update a user's name only if the user exists, otherwise create a new user with that name using Prisma in NestJS. Which approach correctly handles this logic?

hard

A. Use delete then create to replace the user

B. Call update and if it fails, call create manually

C. Use findMany then create without update

D. Use upsert with where, update, and create objects

Solution

1. Step 1: Understand Prisma's upsert method

   The upsert method updates a record if it exists or creates it if not, combining both actions safely.

2. Step 2: Identify correct usage for conditional update or create

   Using upsert with where to find the user, update for changes, and create for new record is the best practice.

3. Final Answer:

   Use upsert with where, update, and create objects -> Option D

4. Quick Check:

   Conditional update or create = upsert [OK]

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

Common Mistakes:

• Manually catching update errors to create
• Using findMany without update
• Deleting before creating wastes operations