Schema

Schema Structure

datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
}

generator client {
  provider = "prisma-client-js"
}

model User {
  id        Int      @id @default(autoincrement())
  email     String   @unique
  name      String?
  role      Role     @default(USER)
  posts     Post[]
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt
}

model Post {
  id        Int      @id @default(autoincrement())
  title     String
  content   String?
  published Boolean  @default(false)
  author    User     @relation(fields: [authorId], references: [id])
  authorId  Int
  createdAt DateTime @default(now())

  @@index([authorId])
}

enum Role {
  USER
  ADMIN
}

Field Types

• String — text data
• Int — 32-bit integer
• BigInt — 64-bit integer
• Float — floating point
• Decimal — exact decimal
• Boolean — true/false
• DateTime — timestamp
• Json — JSON data (not available on SQLite)
• Bytes — binary data

Modifiers: ? = optional/nullable, [] = list/array

Key Attributes

Field-Level

• @id — primary key
• @unique — unique constraint
• @default(value) — default: autoincrement(), uuid(), cuid(), now(), dbgenerated("expr")
• @updatedAt — auto-updates on every save
• @relation(fields: [fk], references: [pk]) — define foreign key relation
• @map("column_name") — custom column name in DB
• @db.VarChar(255) — native type annotation

Block-Level

• @@id([field1, field2]) — composite primary key
• @@unique([field1, field2]) — composite unique constraint
• @@index([field1, field2]) — database index
• @@map("table_name") — custom table name in DB

Relation Patterns

One-to-Many

model User {
  posts Post[]
}
model Post {
  author   User @relation(fields: [authorId], references: [id])
  authorId Int
}

One-to-One

model User {
  profile Profile?
}
model Profile {
  user   User @relation(fields: [userId], references: [id])
  userId Int  @unique
}

Many-to-Many (implicit)

model Post { tags Tag[] }
model Tag  { posts Post[] }

Self-Relation

model Employee {
  id           Int        @id @default(autoincrement())
  manager      Employee?  @relation("Management", fields: [managerId], references: [id])
  managerId    Int?
  subordinates Employee[] @relation("Management")
}

Referential Actions

On @relation: onDelete: Cascade | Restrict | NoAction | SetNull | SetDefault

model Post {
  author   User @relation(fields: [authorId], references: [id], onDelete: Cascade)
  authorId Int
}

Edge Cases

• Only one datasource block is allowed per schema
• @unique on a relation scalar field makes the relation one-to-one
• MongoDB requires @map("_id") on the id field and @db.ObjectId for ObjectId types
• Composite primary keys (@@id) cannot use autoincrement()
• Self-relations require a named relation string to disambiguate
• Multiple relations between the same two models require distinct relation names
• @updatedAt only works on DateTime fields
• Json type is not available on SQLite