Input Validation

🔋 ZenStack vs Prisma

Input validation is a ZModel feature and doesn't exist in Prisma.

warning

Input validation is only applied to the ORM APIs like create, update, etc. It's not enforced at the query builder level.

When defining a model field in ZModel, you specify its type, which provides a basic level of runtime validation - when an incompatible value is passed to the field during creation or update, the ORM engine will reject the operation.

However, oftentimes you want to express more fine-grained validation rules, such as field length, string format, or numeric range, etc. ZModel provides a set of built-in field-level validation attributes, like @length, @email, etc., for this purpose. See reference guide for more details.

To support more complex rules, a powerful @@validate model-level attribute is provided to allow expression rules using multiple fields and logical operators. Inside the @@validate attribute, functions like length(), isEmail(), etc. are available for building up expressions. See reference guide for the complete list of available functions.

Arguments of mutation operations are validated before sending them to the database. When a validation rule is violated, an InputValidationError exception is thrown, containing details about the violations.

Internally, ZenStack uses Zod to perform validation. Most of the attributes and functions are 1:1 mapped to Zod APIs.

Samples

Click here to open an interactive playground.

zenstack/schema.zmodel

datasource db {
    provider = 'sqlite'
}

enum Role {
    USER
    ADMIN
}

model User {
    id     Int    @id @default(autoincrement())
    email  String @unique @email @length(5, 80)
    age    Int    @gte(0) @lt(150)
    role   Role

    @@validate(role != 'ADMIN' || age >= 18, 'Admin must be an adult')
    @@validate(
        role != 'ADMIN' || endsWith(email, 'zenstack.dev'),
        'Admin must have a zenstack email'
    )
}

main.ts

import { createClient } from './db';

async function main() {
  const db = await createClient();

  try {
    // invalid email
    await db.user.create({
      data: { email: 'abc@xyz', age: 20, role: 'USER' }
    })
  } catch (err) {
    console.log('Got expected error:', (err as Error).message);
  }

  try {
    // admin is not an adult, plus not having a zenstack email
    await db.user.create({
      data: { email: 'john@gmail.com', age: 16, role: 'ADMIN' }
    });
  } catch (err) {
    console.log('Got expected error:', (err as Error).message);
  }

  // success
  const user = await db.user.create({
    data: { email: 'john@zenstack.dev', age: 20, role: 'ADMIN' }
  });
  console.log('User create:', user);
}

main();