Relations in Prisma in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a one-to-many relation in Prisma schema.

NestJS

model User {
  id    Int     @id @default(autoincrement())
  posts Post[] [1]
}

model Post {
  id     Int  @id @default(autoincrement())
  userId Int
  user   User @relation(fields: [userId], references: [id])
}

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A@unique

B@relation(fields: [userId], references: [id])

C@relation("UserPosts")

D@default(0)

Attempts:

3 left

💡 Hint

Common Mistakes

Using @unique on the array field instead of @relation

Omitting the @relation decorator on the array side

Using @default on relation fields

The @relation("UserPosts") decorator names the relation and connects the posts field in User to the user field in Post, establishing a one-to-many relation.

2fill in blank

medium

Complete the code to fetch a user with their posts using Prisma Client.

NestJS

const userWithPosts = await prisma.user.findUnique({
  where: { id: userId },
  [1]: { posts: true }
});

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Aselect

Binclude

Cwith

Drelations

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'select' instead of 'include' to fetch relations

Using non-existent options like 'with' or 'relations'

The include option tells Prisma Client to fetch related records, here the posts of the user.

3fill in blank

hard

Fix the error in the Prisma schema relation definition.

NestJS

model Profile {
  id     Int  @id @default(autoincrement())
  userId Int  @unique
  user   User [1]
}

model User {
  id      Int      @id @default(autoincrement())
  profile Profile?
}

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A@relation(fields: [userId], references: [id])

B@unique

C@default(0)

D@id

Attempts:

3 left

💡 Hint

Common Mistakes

Using @unique alone without @relation

Missing fields or references in the relation decorator

The @relation(fields: [userId], references: [id]) decorator correctly defines the foreign key and references for the one-to-one relation.

4fill in blank

hard

Fill both blanks to define a many-to-many relation in Prisma schema.

NestJS

model Student {
  id       Int       @id @default(autoincrement())
  courses  Course[]  [1]
}

model Course {
  id        Int        @id @default(autoincrement())
  students  Student[]  [2]
}

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A@relation("StudentCourses")

B@relation(fields: [studentId], references: [id])

C@relation("StudentCourses", references: [id])

D@unique

Attempts:

3 left

💡 Hint

Common Mistakes

Using different relation names on each side

Adding fields and references on the array side in many-to-many

Both sides of a many-to-many relation use the same @relation name to link the two models.

5fill in blank

hard

Fill all three blanks to create a nested create operation with relations in Prisma Client.

NestJS

const newUser = await prisma.user.create({
  data: {
    name: 'Alice',
    posts: {
      [1]: [
        { title: 'First Post', content: 'Hello' },
        { title: 'Second Post', content: 'World' }
      ]
    },
    profile: {
      [2]: {
        bio: 'Developer'
      }
    },
    [3]: true
  }
});

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

Acreate

Cinclude

Dselect

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'select' instead of 'include' to fetch relations

Omitting 'create' for nested related records

Use create to nest creation of related records, and include to fetch related data in the result.