defaults (@default)

This is the equivalent of Prisma's @default(). It automatically sets default values for fields during create operations.

Schema vs. Constructor

When using the CLI, this setting is written in schema.prisma. When using the GAS editor alone, you pass it to the GassmaClient constructor (the examples on the rest of this page use the constructor form).

	How to write it
Schema (CLI)	role String @default("USER")
Constructor (GAS editor)	defaults: { Users: { role: "USER" } }

model Users {
  id        Int      @id
  name      String
  role      String   @default("USER")
  createdAt DateTime @default(now())
}

For how to write schemas, see Schema.

Basic Usage

const gassma = new Gassma.GassmaClient({
  defaults: {
    Users: {
      role: "USER",
      createdAt: () => new Date(),
    },
  },
});

// Default values are automatically applied during create
gassma.Users.create({
  data: { name: "Alice" },
});
// => { name: "Alice", role: "USER", createdAt: 2026-03-14T... }

Static Values and Functions

You can specify both fixed values and functions as default values.

Type	Example	Behavior
Static value	role: "USER"	Sets the same value every time
Function	createdAt: () => new Date()	Evaluated on each invocation

Applicable Methods

Method	Applied
create	✅
createMany / createManyAndReturn	✅
upsert (create part only)	✅

Behavior with Explicit Values

If a field is explicitly specified (including null), the default value is not applied.

gassma.Users.create({
  data: { name: "Alice", role: "ADMIN" },
});
// => role is "ADMIN" (default value "USER" is not applied)

Validation of Default Values

Values produced as defaults go through the same validation as values written directly in data. If a default returns something a cell cannot hold, a GassmaInvalidValueError is thrown and no rows are written.

const gassma = new Gassma.GassmaClient({
  defaults: {
    Users: { age: () => NaN },
  },
});

gassma.Users.createMany({ data: [{ name: "Alice" }] });
// => Invalid value for argument `age`. Expected a finite number, but received NaN.

Here {argumentName} is the column name. NaN / Infinity / -Infinity, invalid Dates (Invalid Date) and objects other than Date are covered. For details, see the error list.