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Change the data model

Data Model in Marblism​

In Marblism, your data models are defined in the /models/models.zmodel file. This file uses the ZenStack schema language, which is an extension of Prisma's schema definition language.

This powerful combination allows for efficient database operations, type safety, auto-generated back-end and enhanced features like permissions.

Here's a basic example of how a model might look:

model User {
  id    Int     @id @default(autoincrement())
  email String  @unique
  name  String?
  posts Post[]

  @@allow('create,read', true)
  @@allow('update,delete', auth() == this)
}

model Post {
  id        Int      @id @default(autoincrement())
  title     String
  content   String?
  published Boolean  @default(false)
  author    User     @relation(fields: [authorId], references: [id])
  authorId  Int

  @@allow('read', published == true)
  @@allow('create,update,delete', auth() == author)
}

In this example, we define two models: User and Post. Each model has fields with types and attributes. The @@allow directives are ZenStack-specific and define access control rules.

Adding a new model​

To add a new model to your application:

  1. Open the models.zmodel file in your project.
  2. Define your new model using ZenStack schema syntax. For example:
model NewModel {
  id          Int      @id @default(uuid())
  name        String
  dateCreated DateTime @default(now())
}

Editing a model property​

To edit a property of an existing model:

  1. Locate the model in your models.zmodel file.
  2. Modify the property as needed. For example, changing a field type or adding a new field:
model ExistingModel {
  id          Int      @id @default(uuid())
  name        String
  age         Int?      // New field
  content     String @default('')  // New field with an empty default value
}
tip

Tip: to avoid having to deal with migration always add fields as optional (using the '?' suffix) or give them a default value.

Applying changes​

After modifying your data model, you need to apply these changes to your API and database.

When using the workspace, a popup will appear automatically as soon as you edit your models in the models.zmodel file. This popup allows you to run both pnpm run crud:sync and pnpm run database:sync commands with a single click, streamlining the process of applying your model changes.

Key Features​

  1. Type Safety: ZenStack inherits Prisma's strong typing, ensuring type safety across your application.

  2. Access Control: Use @@allow and @@deny directives to define fine-grained access control rules directly in your schema.

  3. Validation: Define custom validation rules using ZenStack's enhanced schema language.

  4. Relations: Define relationships between models easily, just like in Prisma.

  5. Auto-generated CRUD Operations: Marblism automatically generates CRUD endpoints based on your ZenStack schema.

Using Your Models​

Once defined, these models are used throughout your Marblism application. The auto-generated API endpoints will allow you to interact with your data. Read more about it here: Querying the API.

For more detailed information on ZenStack's features and syntax, refer to the official ZenStack documentation.