Prisma: 2.0.0-preview023 Release

Today, we are issuing the twenty-third Preview release: 2.0.0-preview023 (short: preview023).

This release contains breaking changes, be sure to read the notes below before upgrading!

Breaking changes

Cursor-pagination API changed in Prisma Client

Because Prisma now supports composite unique constraints, the before and after API for cursor-pagination (which is based on unique fields) also changes. The cursor is now wrapped in an object which might have multiple fields.

Assume you have this Prisma model:

model Post {
  id        Int     @default(autoincrement())
  title     String  @unique
  content   String?
}

Before

const cursor = 42
const posts = await prisma.post.findMany({
  after: cursor
})

After

const cursor = 42
const posts = await prisma.post.findMany({
  after: { id: cursor }
})

Removed the enabled property in datasource blocks

The enabled property was removed from the datasource blocks.

Major improvements

In this issue, we're lifting a major limitation of Prisma which always required every model to have exactly one primary key constraint. In the Prisma schema, this primary key was represented using the @id attribute.

With this release, you can now have tables:

• without primary keys (but unique constraints)
• with composite primary keys
• with composite unique constraints

Read below for more information on each of these new features. Lifting these limitations was a major effort, please be sure to report any bugs or other issues you encounter using these new features!

Allows models without IDs

In previous Prisma versions, there was a hard requirement that every model in your Prisma schema needed to have a single @id field (which maps to a primary key constraint in the underlying database). This requirement is now lifted and your models don't need primary key constraints any more to be compatible with Prisma 2 (they do need at least one unique constraint though).

For example, this data model is now valid:

model Post {
  title     String  @unique
  content   String?
  published Boolean @default(false)
  author    User?
}

model User {
  email String  @unique
  name  String?
  posts Post[]
}

Composite primary keys

As of this release, Prisma supports composite IDs (which map to multi-column primary key constraints in the underlying database). Composite IDs are defined on a "model-level" using the @@id attribute. Here's an example:

model User {
  firstName String
  lastName  String
  email     String

  @@id([firstName, lastName])
}

This also impacts the Prisma Client API and how you're querying for single records, e.g. in findOne, update or delete queries where you need to identify a record by its primary key (or another unique field). These queries take the following type as input:

export type UserWhereUniqueInput = {
  firstName_lastName?: FirstNameLastNameCompoundUniqueInput | null
}

export type FirstNameLastNameCompoundUniqueInput = {
  firstName: string
  lastName: string
}

This means, in order to query for a User record, you need to provide both firstName and lastName fields wrapped inside a firstName_lastName object:

const user = await prisma.user.findOne({
  where: {
    firstName_lastName: {
      firstName: "Jane",
      lastName: "Doe"
    }
  }
})

Composite unique indexes / constraints

As of this release, Prisma also supports composite unique constraints (which map to multi-column unique constraints in the underlying database). Composite unique constraints are defined on a "model-level" using the @@unique attribute.

Note: Primary key and unique constraints are very similar but have some differences on the database-level. You can learn more about the differences here.

Here's an example:

model User {
  firstName String
  lastName  String
  email     String

  @@unique([firstName, lastName])
}

This also impacts the Prisma Client API and how you're querying for single records, e.g. in findOne, update or delete queries where you need to identify a record by its primary key (or another unique field). These queries take the following type as input:

export type UserWhereUniqueInput = {
  firstName_lastName?: FirstNameLastNameCompoundUniqueInput | null
}

export type FirstNameLastNameCompoundUniqueInput = {
  firstName: string
  lastName: string
}

This means, in order to query for a User record, you need to provide both firstName and lastName fields wrapped inside a firstName_lastName object:

const user = await prisma.user.findOne({
  where: {
    firstName_lastName: {
      firstName: "Jane",
      lastName: "Doe"
    }
  }
})

Introspection now recognizes default constraints

Prisma's introspection now reconized DEFAULT constraints that are defined on a column. These constraints are represented in the generated Prisma schema using the @default attribute.

Optimize nested GraphQL queries that use Prisma Client ("dataloader")

When building a GraphQL server with Prisma Client, it wasn't easy to avoid the n+1 problem with nested queries. This release of Prisma Client optimizes the execution of GraphQL nested queries by batching requests against the database.

Fixes and improvements per Prisma 2 repository

prisma2

• Add @prisma/studio-types to prisma2 devDependencies
• generate --watch broken
• Error: [/rustc/5e1a799842ba6ed4a57e91f7ab9435947482f7d8/src/libcore/macros/mod.rs:15:40] called Option::unwrap() on a None value
• Add docs for .raw template literal API with parameters #1583
• Unclear rust error: called Option::unwrap() on a None value
• [Introspection] Order of fields in @@index changes with alpha 808 for PostgreSQL
• add error formatting docs
• add docs for utility types
• remove mentions of mongodb
• Remove MongoDB from documentation
• Document SQLite connection strings
• Error: P4001 The introspected database was empty: undefined url or file if sqlite should be displayed instead of undefined
• Clean up branches
• Document MySQL unix socket connection usage
• Error: Schema parsing thread 'main' panicked at 'assertion failed: (left == right)
• [Introspection] "Error: Schema parsing thread 'main' panicked at 'Encountered impossible datamodel declaration during parsing: "
• [Introspection] Postgres serial type is missing @default(autoincrement())
• Document workarounds for No-identifier-tables
• Improve .raw template literal API with parameters
• Document error formatting
• --experimental flag order
• generate shows "Downloading ..." every time when a custom binaryTarget is specified
• [Introspection] Investigate field/model types
• Remove enabled field from datasource block
• Query Engine failed ENOENT
• Certificate identity files are required in both prisma folder and in the folder from which lift is executed
• Do not require environment variables for generate
• Prisma is not including columns of Postgres type 'time without time zone' in schema

prisma-client-js

• Improve reserved words / denylist for code generation
• Implement new # private fields for PrismaClient
• Lowercasing of model and field names
• .raw template literal API with parameters
• JSON.parse(dmmfString) fails on prisma schema with docs
• Fix Error's meta property typing
• improve download logic
• Test Prisma Client with pgBouncer
• "Note, that by providing native, Prisma Client automatically resolves rhel-openssl-1.0.x"
• Better runtime error handling for missing binaries
• Document utility types
• File name (datamodel.mdl) and client name (Photon JS) in graphic in README need to be updated
• Hide top-level client properties (as they are visible via JS code intellisense)
• tslint: Invalid 'await' of a non-Promise value

prisma-engines

• [Query Core] Housekeeping
• DMMF: add information about multi field uniques
• do not fail on missing env vars in dmmf
• Only build relevant binaries in connector-test-kit
• Return a known error on invalid/absent database string
• Fix crash on building of foreign keys overlapping with PK
• Panic for empty env var
• Implementing execute raw tests in rust
• Temporarily Drop Relations on Compound Ids
• Test explicit enum default migrations with @map
• Any Relation References
• Remove lazy-static
• Fix postgres field ordering inside indexes in sql schema describer
• Test index fields ordering is preserved in postgres sql-schema-describer
• Take @map into account when migrating enum values
• Implement diffing of enum value directives
• Introspect Serial as Autoincrement on Postgres
• Optimize the amount of queries sent by sql-schema-describer on postgres
• Propagate quaint timeout messages to introspection connector errors
• Optimized Postgres Introspection
• Add rule for doc-comments to data model Parser
• Find one optimization
• Do not add @map to virtual back relation fields
• Remap Invalid Enum Values
• Single-field @@unique is not handled correctly.
• EPIC: @relation(references: ..) for multiple fields
• Query Engine: Loosen id requirement. At least one unique criteria is enough.
• EPIC: Loosen id requirement. At least one unique criteria is enough.