Overview

Objects are inline data structures defined with the object {} keyword in Cerial schemas. Unlike models, objects are stored directly within the parent model — they do not create separate database tables, have no id field, and cannot participate in relations.

Think of objects as structured sub-documents embedded inside a model record. A User with an address Address field stores the address data inline within the user record itself, not in a separate Address table.

object Address {
  street String
  city String
  state String
  zipCode String?
}

model User {
  id Record @id
  name String
  address Address
  shipping Address?
}

const user = await client.db.User.create({
  data: {
    name: 'Jane Doe',
    address: { street: '123 Main St', city: 'NYC', state: 'NY' },
    // shipping omitted — stored as NONE (absent)
  },
});

console.log(user.address.city); // 'NYC'
console.log(user.shipping);     // undefined

Key Rules

1. No id field — Objects have no identity. They exist only as part of their parent model.
2. No relations — Record and Relation fields are not allowed inside objects.
3. Can reference other objects — Objects can nest other objects to any depth.
4. Support optional and array fields — Use ? for optional fields and [] for arrays, just like models.
5. Optional object fields produce field?: ObjectType — There is no | null in the type. Objects are either present or absent (NONE), never null.
6. Array object fields default to [] on create — Omitting an array object field produces an empty array, same as primitive arrays.
7. Support a subset of decorators — Only certain decorators are allowed on object fields (see below).
8. Indexes are independent per embedding path — If an object with @unique is used on multiple model fields, each field gets its own independent constraint.

Supported Decorators

Object fields support a subset of decorators. Relation and identity decorators are not applicable since objects have no identity or relations.

Generated Types

Each object definition generates a set of TypeScript types:

Objects do not generate GetPayload, Include, Create, Update, or Model types — those are exclusive to models.

Sections

• Defining Objects — Schema syntax for declaring object types
• Object Fields on Models — Using objects as required, optional, or array fields
• Primitive Arrays in Objects — Using primitive array fields inside objects
• Select — Sub-field selection on embedded objects
• Where Filtering — Filtering by object sub-fields
• Updating Objects — Partial merge and full replacement
• Ordering — Sorting by embedded object fields