# Driver Adapters

These examples apply to **Prisma ORM 7 SQL clients** during a 6-to-7 upgrade. They do not configure Prisma 8; use the installed package-owned `prisma-8` runtime guidance for that version.

MongoDB should not follow this path. There is no published MongoDB `@prisma/adapter-*` package, and MongoDB projects should remain on the latest Prisma 6.x release instead of trying to fit into the Prisma 7 SQL adapter model.

## Why Driver Adapters?

- No native engine binary in the Prisma Client SQL path
- Smaller bundle size
- Better serverless/edge compatibility
- Uses native Node.js database drivers
- More control over connection pooling

## Available Adapters

| Database | Adapter Package | Underlying Driver |
|----------|-----------------|-------------------|
| PostgreSQL | `@prisma/adapter-pg` | `pg` |
| MySQL / MariaDB | `@prisma/adapter-mariadb` | `mariadb` |
| SQLite | `@prisma/adapter-better-sqlite3` | `better-sqlite3` |
| Prisma Postgres (Node.js) | `@prisma/adapter-pg` | `pg` |
| Prisma Postgres (edge/serverless) | `@prisma/adapter-ppg` | `@prisma/ppg` |
| SQL Server | `@prisma/adapter-mssql` | `mssql` |
| Neon | `@prisma/adapter-neon` | `@neondatabase/serverless` |
| PlanetScale | `@prisma/adapter-planetscale` | `@planetscale/database` |
| Turso/libSQL | `@prisma/adapter-libsql` | `@libsql/client` |
| D1 (Cloudflare) | `@prisma/adapter-d1` | Cloudflare D1 |

## Installation

### PostgreSQL

```bash
npm install @prisma/adapter-pg
```

### MySQL

```bash
npm install @prisma/adapter-mariadb mariadb
```

### SQLite

```bash
npm install @prisma/adapter-better-sqlite3
```

### Prisma Postgres

```bash
npm install @prisma/adapter-pg pg
```

### SQL Server

```bash
npm install @prisma/adapter-mssql mssql
```

## Configuration

### PostgreSQL

```typescript
import { PrismaClient } from '../generated/client'
import { PrismaPg } from '@prisma/adapter-pg'

const adapter = new PrismaPg({
  connectionString: process.env.DATABASE_URL
})

const prisma = new PrismaClient({ adapter })
```

### MySQL

```typescript
import { PrismaClient } from '../generated/client'
import { PrismaMariaDb } from '@prisma/adapter-mariadb'

const adapter = new PrismaMariaDb({
  host: 'localhost',
  port: 3306,
  connectionLimit: 5,
  user: process.env.MYSQL_USER,
  password: process.env.MYSQL_PASSWORD,
  database: process.env.MYSQL_DATABASE,
})

const prisma = new PrismaClient({ adapter })
```

### SQLite

```typescript
import { PrismaClient } from '../generated/client'
import { PrismaBetterSqlite3 } from '@prisma/adapter-better-sqlite3'

const adapter = new PrismaBetterSqlite3({
  url: process.env.DATABASE_URL || 'file:./dev.db'
})

const prisma = new PrismaClient({ adapter })
```

### Neon (Serverless PostgreSQL)

```typescript
import { PrismaClient } from '../generated/client'
import { PrismaNeon } from '@prisma/adapter-neon'

const adapter = new PrismaNeon({
  connectionString: process.env.DATABASE_URL
})

const prisma = new PrismaClient({ adapter })
```

### Prisma Postgres

```typescript
import { PrismaClient } from '../generated/client'
import { PrismaPg } from '@prisma/adapter-pg'

const adapter = new PrismaPg({
  connectionString: process.env.DATABASE_URL,
})

const prisma = new PrismaClient({ adapter })
```

### Prisma Postgres serverless driver

```typescript
import { PrismaClient } from '../generated/client'
import { PrismaPostgresAdapter } from '@prisma/adapter-ppg'

const prisma = new PrismaClient({
  adapter: new PrismaPostgresAdapter({
    connectionString: process.env.PRISMA_DIRECT_TCP_URL,
  }),
})
```

### SQL Server

```typescript
import { PrismaClient } from '../generated/client'
import { PrismaMssql } from '@prisma/adapter-mssql'

const adapter = new PrismaMssql({
  server: 'localhost',
  port: 1433,
  database: 'mydb',
  user: process.env.SQLSERVER_USER,
  password: process.env.SQLSERVER_PASSWORD,
  options: {
    encrypt: true,
    trustServerCertificate: true,
  },
})

const prisma = new PrismaClient({ adapter })
```

## Connection Pool Configuration

Driver adapters use the underlying driver's pool settings, which differ from v6 defaults.

### PostgreSQL with custom pool

```typescript
import { PrismaPg } from '@prisma/adapter-pg'

const adapter = new PrismaPg({
  connectionString: process.env.DATABASE_URL,
  // Pool configuration
  max: 10,                    // Maximum connections
  idleTimeoutMillis: 30000,   // Close idle connections after 30s
  connectionTimeoutMillis: 5000, // Connection timeout (v6 default was 5s)
})
```

### Matching v6 behavior

```typescript
const adapter = new PrismaPg({
  connectionString: process.env.DATABASE_URL,
  connectionTimeoutMillis: 5000,  // v6 used 5 second timeout
})
```

## SSL Configuration

### Accept self-signed certificates

```typescript
const adapter = new PrismaPg({
  connectionString: process.env.DATABASE_URL,
  ssl: {
    rejectUnauthorized: false  // Accept self-signed certs
  }
})
```

### Proper SSL configuration

```typescript
const adapter = new PrismaPg({
  connectionString: process.env.DATABASE_URL,
  ssl: {
    ca: fs.readFileSync('/path/to/ca-cert.pem'),
    rejectUnauthorized: true
  }
})
```

## Migration from v6

### Before (v6)

```typescript
import { PrismaClient } from '@prisma/client'

const prisma = new PrismaClient({
  datasources: {
    db: { url: process.env.DATABASE_URL }
  }
})
```

### After (v7)

```typescript
import { PrismaClient } from '../generated/client'
import { PrismaPg } from '@prisma/adapter-pg'

const adapter = new PrismaPg({
  connectionString: process.env.DATABASE_URL
})

const prisma = new PrismaClient({ adapter })
```

## Singleton Pattern

```typescript
// lib/prisma.ts
import { PrismaClient } from '../generated/client'
import { PrismaPg } from '@prisma/adapter-pg'

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

const adapter = new PrismaPg({
  connectionString: process.env.DATABASE_URL!
})

export const prisma = globalForPrisma.prisma ?? new PrismaClient({ adapter })

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