Creating the Prisma schema

Manually create the Prisma schema

Open the prisma/schema.prisma file and replace the default configurations with the following:

prisma/schema.prisma
1
2datasource db {
3  provider = "mongodb"
4  url      = env("DATABASE_URL")
5}
6
7generator client {
8  provider        = "prisma-client-js"
9  previewFeatures = ["mongoDb"]
10}
11
12model Post {
13  id        String    @id @default(dbgenerated()) @map("_id") @db.ObjectId
14  slug      String    @unique
15  title     String
16  body      String
17  comments  Comment[]
18  user      User      @relation(fields: [userId], references: [id])
19  userId    String    @db.ObjectId
20}
21
22// Comments contain a comment string and connect back to the post.
23// postId must have @db.ObjectId to match up with Post's id type
24model Comment {
25  id      String  @id @default(dbgenerated()) @map("_id") @db.ObjectId
26  post    Post    @relation(fields: [postId], references: [id])
27  postId  String  @db.ObjectId
28  comment String
29}
30
31model User {
32  id      String   @id @default(dbgenerated()) @map("_id") @db.ObjectId
33  email   String   @unique
34  name    String?
35  posts   Post[]
36}
37

Because MongoDB is currently a preview feature, you need to explicitly define that in the generator block with previewFeatures = ["mongoDb"].

There are also a number of subtle differences in how the schema is setup when compared to relational databases like PostgreSQL.

For example, the underlying ID field name is always _id and must be mapped with @map("_id").

For more information check out the MongoDB schema reference.