DataModelLM - Visual Data Modeling

DataModelLM is Nimbalyst's visual editor for creating database schemas using Prisma format. It displays entity-relationship diagrams with a visual canvas.

When to Use DataModelLM

• Designing database schemas
• Creating entity relationship diagrams (ERDs)
• Planning data models for applications
• Working with Prisma schemas
• Any visual data modeling task

File Format

• Extension: .prisma
• Format: Prisma schema with special metadata header
• Location: Any directory (commonly workspace root or models/, schema/)

Required Header

Every DataModelLM file MUST start with a @nimbalyst metadata comment:

prisma
// @nimbalyst {"viewport":{"x":0,"y":0,"zoom":1},"positions":{},"entityViewMode":"standard"}

Basic Structure

prisma
// @nimbalyst {"viewport":{"x":0,"y":0,"zoom":1},"positions":{},"entityViewMode":"standard"}

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

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

Supported Types

Scalar Types

• Int, BigInt, Float, Decimal
• String, Boolean
• DateTime, Json, Bytes

Modifiers

• ? - Optional field
• [] - Array/list

Attributes

• @id - Primary key
• @unique - Unique constraint
• @default(value) - Default value
• @updatedAt - Auto-update timestamp
• @relation - Define relationships

Relationship Patterns

One-to-Many

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

One-to-One

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

Many-to-Many (Implicit)

prisma
model Post {
  categories Category[]
}
model Category {
  posts Post[]
}

Best Practices

1. Always include the @nimbalyst header - Required for visual editor
2. Use meaningful model names - PascalCase, singular (User not Users)
3. Include timestamps - Add createdAt and updatedAt to most models
4. Define explicit relations - Always specify @relation with fields and references