How to insert only unique values to a field using Hypi Directive(@unique)

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In the previous post, we have seen how to check null string using @notEmpty directive

In this post, we will see how to insert only unique values to a field using Hypi directive.

Again a brief info on Hypi Directives:

  • Hypi directives help to customise the behaviour of the data fields.
  • @ character depicts the Hypi directive. It is followed by a series of characters.
  • A directive may have a list of optional named arguments.
  • Disable directive by adding # in front of it.

Let’s check the @unique directive!
strUnique: String @unique

  • Use the @unique directive to ensure no duplicate values in a field.
  • While creating an object, no previously inserted values are allowed in a field.
  • It returns an error if a repeated value is inserted in a field while creating a new object

We will work with the below schema.

type DirectiveObj {
    strUnique: String @unique
}

Sample Query

Let’s see how the @unique directive works. We have already inserted the value in the strUnique field. Again adding the same value - Hypi in the same field results in an error.

mutation {
  upsert(values: { DirectiveObj: { strUnique: "Hypi" } }) {
    id
  }
}
#result
{
  "data": {
    "upsert": [
      {
        "id": "01FNBDPVC4GHK67KP0CEJRT1J2"
      }
    ]
  },
  "errors": [
    {
      "message": "'DirectiveObj.strUnique' already exists with a value of Hypi",
      "extensions": {}
    }
  ]
}

Check the POSTMAN collection for the @unique directive in different programming languages! Click </> and choose the programming language of your choice.

Don’t forget to insert your own Authorization key and Hypi Domain under Headers to test the results!

Run in Postman