Prisma Database Setup

# Prisma Database Setup

Comprehensive guides for configuring Prisma ORM with various database providers.

## When to Apply

Reference this skill when: - Initializing a new Prisma project - Switching database providers - Configuring connection strings and environment variables - Troubleshooting database connection issues - Setting up database-specific features - Generating and instantiating Prisma Client

## Rule Categories by Priority

| Priority | Category | Impact | Prefix | |----------|----------|--------|--------| | 1 | Provider Guides | CRITICAL | provider names | | 2 | Prisma Postgres | HIGH | `prisma-postgres` | | 3 | Client Setup | CRITICAL | `prisma-client-setup` |

## System Prerequisites

- **Node.js 20.19.0+** - **TypeScript 5.4.0+**

## Bun Runtime

If you're using Bun, run Prisma CLI commands with `bunx --bun prisma ...` so Prisma uses the Bun runtime instead of falling back to Node.js.

## Supported Databases

| Database | Provider String | Notes | |----------|-----------------|-------| | PostgreSQL | `postgresql` | Default, full feature support | | MySQL | `mysql` | Widespread support, some JSON diffs | | SQLite | `sqlite` | Local file-based, no enum/scalar lists | | MongoDB | `mongodb` | Mongo-specific workflow; do not apply SQL driver-adapter guidance | | SQL Server | `sqlserver` | Microsoft ecosystem | | CockroachDB | `cockroachdb` | Distributed SQL, Postgres-compatible | | Prisma Postgres | `postgresql` | Managed serverless database |

## Configuration Files

Your configuration shape depends on the provider and Prisma major version:

1. **All providers** use **`prisma/schema.prisma`**. 2. **Prisma 7 SQL setups** typically use **`prisma.config.ts`** for datasource URLs. 3. **MongoDB projects should stay on Prisma 6.x**, keep `url = env("DATABASE_URL")` in the schema, and continue using the classic MongoDB setup.

## Driver Adapters

The standard SQL workflow uses a driver adapter. Choose the adapter and driver for your database and pass the adapter to `PrismaClient`.

| Database | Adapter | JS Driver | |----------|---------|-----------| | PostgreSQL | `@prisma/adapter-pg` | `pg` | | CockroachDB | `@prisma/adapter-pg` | `pg` | | Prisma Postgres (Node.js) | `@prisma/adapter-pg` | `pg` | | Prisma Postgres (edge/serverless) | `@prisma/adapter-ppg` | `@prisma/ppg` | | MySQL / MariaDB | `@prisma/adapter-mariadb` | `mariadb` | | SQLite | `@prisma/adapter-better-sqlite3` | `better-sqlite3` | | SQLite (Turso/LibSQL) | `@prisma/adapter-libsql` | `@libsql/client` | | SQL Server | `@prisma/adapter-mssql` | `node-mssql` |

MongoDB should not follow the Prisma 7 SQL adapter workflow. Use the latest Prisma 6.x release for MongoDB projects and do not install a SQL `@prisma/adapter-*` package for it.

Example (PostgreSQL):

```ts import 'dotenv/config' 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 Client Setup (Required)

Prisma Client must be installed and generated for any database.

1. Install Prisma CLI and Prisma Client: ```bash npm install prisma --save-dev npm install @prisma/client ```

1. Add a generator block (`prisma-client` requires an explicit output path): ```prisma generator client { provider = "prisma-client" output = "../generated" } ```

1. Generate Prisma Client: ```bash npx prisma generate ```

1. For SQL providers, instantiate Prisma Client with the database-specific driver adapter: ```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 }) ```

1. Re-run `prisma generate` after every schema change.

## Quick Reference

### PostgreSQL ```prisma datasource db { provider = "postgresql" }

generator client { provider = "prisma-client" output = "../generated" } ```

### MySQL ```prisma datasource db { provider = "mysql" }

generator client { provider = "prisma-client" output = "../generated" } ```

### SQLite ```prisma datasource db { provider = "sqlite" }

generator client { provider = "prisma-client" output = "../generated" } ```

### MongoDB ```prisma datasource db { provider = "mongodb" url = env("DATABASE_URL") }

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

For MongoDB, stay on the latest Prisma 6.x line and keep the connection URL in `schema.prisma`. Do not move a MongoDB project to the Prisma 7 SQL adapter setup. If a MongoDB project asks about upgrading Prisma versions, route to the `prisma-mongodb-upgrade` skill (stay-on-v6 vs Prisma Next is the real decision; Prisma 7 is not an option).

## Rule Files

See individual rule files for detailed setup instructions:

``` references/postgresql.md references/mysql.md re