# Patroon: Prisma Client singleton

## lib/prisma.ts

PostgreSQL via `pg` + `@prisma/adapter-pg` (Neon/Vercel).

```ts
import { PrismaClient } from '@prisma/client'
import { Pool } from 'pg'
import { PrismaPg } from '@prisma/adapter-pg'

function createPrismaClient() {
  const url = process.env.DATABASE_URL
  if (!url) throw new Error('DATABASE_URL is not set')

  const pool = new Pool({ connectionString: url })
  const adapter = new PrismaPg(pool)
  return new PrismaClient({
    adapter,
    log: process.env.NODE_ENV === 'development' ? ['error', 'warn'] : ['error'],
  })
}

const globalForPrisma = globalThis as unknown as { prisma: PrismaClient | undefined }

export const prisma = globalForPrisma.prisma ?? createPrismaClient()

if (process.env.NODE_ENV !== 'production') globalForPrisma.prisma = prisma
```

## prisma.config.ts (Prisma v7 vereiste)

```ts
import 'dotenv/config'
import { defineConfig } from 'prisma/config'

export default defineConfig({
  schema: 'prisma/schema.prisma',
  migrations: { path: 'prisma/migrations' },
})
```