/prisma-cli

prisma db pull

Introspects an existing database and updates your Prisma schema to reflect its structure.

Command

prisma db pull [options]

What It Does

• Connects to your database
• Reads the database schema (tables, columns, relations, indexes)
• Updates schema.prisma with corresponding Prisma models
• For MongoDB, samples data to infer schema

Options

Examples

Basic introspection

prisma db pull

Preview without writing

prisma db pull --print

Outputs schema to terminal for review.

Force overwrite

prisma db pull --force

Replaces schema file, losing any manual customizations.

Prerequisites

Configure database connection in prisma.config.ts:

import 'dotenv/config'
import { defineConfig, env } from 'prisma/config'

export default defineConfig({
  schema: 'prisma/schema.prisma',
  datasource: {
    url: env('DATABASE_URL'),
  },
})

Workflow

Starting from existing database

1. Initialize Prisma:

   prisma init

2. Configure database URL

3. Pull schema:

   prisma db pull

4. Review and customize generated schema

5. Generate client:

   prisma generate

Syncing changes from database

When database changes are made outside Prisma:

prisma db pull
prisma generate

Generated Schema Example

Database tables become Prisma models:

-- Database tables
CREATE TABLE users (
  id SERIAL PRIMARY KEY,
  email VARCHAR(255) UNIQUE NOT NULL,
  name VARCHAR(100)
);

CREATE TABLE posts (
  id SERIAL PRIMARY KEY,
  title VARCHAR(255) NOT NULL,
  author_id INTEGER REFERENCES users(id)
);

Becomes:

model users {
  id    Int     @id @default(autoincrement())
  email String  @unique @db.VarChar(255)
  name  String? @db.VarChar(100)
  posts posts[]
}

model posts {
  id        Int    @id @default(autoincrement())
  title     String @db.VarChar(255)
  author_id Int?
  users     users? @relation(fields: [author_id], references: [id])
}

Post-Introspection Cleanup

After db pull, consider:

1. Rename models to PascalCase:

   model User {  // Was: users
     @@map("users")
   }

2. Rename fields to camelCase:

   authorId Int? @map("author_id")

3. Add relation names for clarity:

   author User? @relation("PostAuthor", fields: [authorId], references: [id])

4. Add documentation:

   /// User account information
   model User {
     /// Primary email for authentication
     email String @unique
   }

MongoDB Introspection

For MongoDB, db pull samples documents to infer schema:

prisma db pull

May require manual refinement since MongoDB is schemaless.

Warning

db pull overwrites your schema file. Always:

• Commit current schema before pulling
• Use --print to preview first
• Backup customizations you want to keep