Models and fields

Models describe tables. Fields describe columns and relation endpoints.

This page focuses on scalar fields, defaults, keys, maps, and indexes. Continue with Relations for relation ownership and Enums for enum blocks.

Scalar types and Dart mapping

Optional fields use ?.

model User {
  id    Int    @id @default(autoincrement())
  email String @unique
  name  String?
}

Generated Dart usage:

await db.user.create(
  data: const UserCreateInput(
    email: 'alice@example.com',
    name: 'Alice',
  ),
);

Primary keys

Single-field primary key:

model User {
  id Int @id @default(autoincrement())
}

Compound primary key:

model Membership {
  tenantId Int
  userId   Int

  @@id([tenantId, userId])
}

Generated unique selector for a compound id:

const MembershipWhereUniqueInput.tenantIdUserId(
  tenantId: 7,
  userId: 42,
)

Unique constraints

Single-field unique:

email String @unique

Compound unique:

model UserSession {
  userId    Int
  deviceId  String
  token     String

  @@unique([userId, deviceId])
}

Defaults

Common defaults:

• @default(autoincrement())
• @default(now())
• @default(true) or @default(false)
• @default("literal")
• @default(member) for enum values

model Todo {
  id        Int      @id @default(autoincrement())
  title     String
  done      Boolean  @default(false)
  createdAt DateTime @default(now())
}

@updatedAt

@updatedAt is runtime-aware. The adapters refresh it on updates and also initialize it on create when omitted.

updatedAt DateTime @updatedAt

Maps and physical names

Use @map when the logical field name should differ from the database column name.

model User {
  id        Int      @id @default(autoincrement())
  createdAt DateTime @map("created_at")

  @@map("users")
}

This is especially useful when migrating an existing schema or when your database naming conventions differ from Dart naming conventions.

Indexes

Use @@index for lookup-heavy access paths that are not already covered by @id or @unique.

model Post {
  id        Int      @id @default(autoincrement())
  authorId  Int
  status    String
  createdAt DateTime @default(now())

  @@index([authorId, status])
  @@index([createdAt])
}

Lists

List fields are mainly used for relations in the current generated-client workflow.

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

The schema validator enforces relation ownership rules and the generated client exposes nested inputs around those list relations.

Continue with

• Relations for one-to-one, one-to-many, self-relations, and compound references
• Enums for enum fields and migration implications
• Native types for provider-specific @db.* coverage