export const metadata = {
  title: `${pageNumber} Data Model’s Primary Key`,
}

# {metadata.title}

In this chapter, you’ll learn how to configure the primary key of a data model.

## primaryKey Method

To set any `id`, `text`, or `number` property as a primary key, use the `primaryKey` method.

For example:

export const highlights = [
  ["4", "primaryKey", "Define the `id` property to be the data model's primary key."]
]

```ts highlights={highlights}
import { model } from "@medusajs/utils"

const MyCustom = model.define("my_custom", {
  id: model.id().primaryKey(),
  // ...
})

export default MyCustom
```

In the example above, the `id` property is defined as the data model's primary key.