Validating that a field is unique OR the same value it was before

[parker-codes]

It wasn't documented for this use case so I hope this helps someone.

Use Case

A user can visit a profile page to update their details (name, email, and phone number). If they change their email, the unique validation rule passes. If they leave it the same, however (which is usually the case), it will fail.

Solution

I had to use the whereNot property and provide it the existing email value, like so:

email: schema.string({ trim: true }, [
  rules.email(),
  rules.unique({
    table: 'users',
    column: 'email',
    // this allows the email to be the same as it was before
    whereNot: { email: user.email },
  }),
]),

(note that the docs mention using refs if you are using schema caching)

[amirhoseinsalimi]

Wow... saved me today!