---
name: prisma-database-setup-mongodb
description: MongoDB Setup. Reference when using this Prisma feature.
license: MIT
metadata:
author: prisma
version: "7.0.0"
---
# MongoDB Setup
**⚠️ WARNING: MongoDB is NOT supported in Prisma ORM v7.**
Support for MongoDB is planned for a future v7 release. If you need MongoDB, you must use **Prisma ORM v6**.
## Prerequisites
- MongoDB 4.2+
- Replica Set configured (required for transactions)
- **Prisma ORM v6.x**
## 1. Schema Configuration (v6)
In `prisma/schema.prisma`:
```prisma
datasource db {
provider = "mongodb"
url = env("DATABASE_URL")
}
generator client {
provider = "prisma-client-js"
}
```
### ID Field Requirement
MongoDB models **must** have a mapped `_id` field using `@id` and `@map("_id")`, usually of type `String` with `auto()` and `db.ObjectId`.
```prisma
model User {
id String @id @default(auto()) @map("_id") @db.ObjectId
email String @unique
name String?
}
```
### Relations
Relations in MongoDB expect IDs to be `db.ObjectId` type.
```prisma
model Post {
id String @id @default(auto()) @map("_id") @db.ObjectId
author User @relation(fields: [authorId], references: [id])
authorId String @db.ObjectId
}
```
## 2. Environment Variable
In `.env`:
```env
DATABASE_URL="mongodb+srv://user:password@cluster.mongodb.net/mydb?retryWrites=true&w=majority"
```
## Migrations vs Introspection
- **No Migrations**: MongoDB is schema-less. `prisma migrate` commands **do not work**.
- **db push**: Use `prisma db push` to sync indexes and constraints.
- **db pull**: Use `prisma db pull` to generate schema from existing data (sampling).
## Common Issues
### "Transactions not supported"
Ensure your MongoDB instance is a **Replica Set**. Standalone instances do not support transactions. Atlas clusters are replica sets by default.
### "Invalid ObjectID"
Ensure fields referencing IDs are decorated with `@db.ObjectId` if the target is an ObjectID.
