Function

Functions are used to provide values for attribute arguments, e.g., current DateTime, an auto-increment Int, etc. They can be used in place of attribute arguments, like:

model Model {
    ...
    serial Int @default(autoincrement())
    createdAt DateTime @default(now())
}

ZModel's standard library provides a set of predefined functions, plugins can provide additional functions, and you can also define your own functions in the schema.

Syntax

Definition

function NAME(PARAMS): RETURN_TYPE {}

• NAME

  Function name. Must be a valid identifier.

• PARAMS

  Parameters. See Parameters for details.

• RETURN_TYPE

  Return type. Must be a valid type as described in Parameters.

Example:

function uuid(version: Int?): String {}

Application

id String @default(FUNC_NAME(ARGS))

• FUNC_NAME

  Function name.

• ARGS

  Argument list. See Parameters for details.

Example:

id String @default(uuid(4))

Parameters

A function can have zero or more parameters. A parameter has a name and a type.

Valid parameter types include:

• String
• Boolean
• Int
• BigInt
• Float
• Decimal
• DateTime
• Bytes
• Any

Parameter's type can also carry the following suffix:

• [] to indicate it's a list type
• ? to indicate it's optional

Predefined functions

uuid()

function uuid(): String {}

Generates a globally unique identifier based on the UUID spec.

cuid()

function cuid(version: Int?): String {}

Generates a unique identifier based on the CUID spec. Pass 2 as an argument to use cuid2.

nanoid()

function nanoid(length: Int?): String {}

Generates an identifier based on the nanoid spec.

ulid()

function ulid(): String {}

Generates a unique identifier based on the ULID spec.

now()

function now(): DateTime {}

Gets current date-time.

autoincrement()

function autoincrement(): Int {}

Creates a sequence of integers in the underlying database and assign the incremented values to the ID values of the created records based on the sequence.

dbgenerated()

function dbgenerated(expr: String): Any {}

Represents default values that cannot be expressed in ZModel (such as random()).

auth()

function auth(): AUTH_TYPE {}

Gets the current login user. The return type is resolved to a model or type annotated with the @@auth attribute, and if not available, a model or type named User.