payload/docs/fields/relationship.mdx

---
title: Relationship Field
label: Relationship
order: 130
desc: The Relationship field provides the ability to relate documents together. Learn how to use Relationship fields, see examples and options.
keywords: relationship, fields, config, configuration, documentation, Content Management System, cms, headless, javascript, node, react, express
---

<Banner>
  The Relationship field is one of the most powerful fields Payload features. It provides for the
  ability to easily relate documents together.
</Banner>

<LightDarkImage
srcLight="https://payloadcms.com/images/docs/fields/relationship.png"
srcDark="https://payloadcms.com/images/docs/fields/relationship-dark.png"
alt="Shows a relationship field in the Payload admin panel"
caption="Admin panel screenshot of a Relationship field"
/>

**Example uses:**

- To add `Product` documents to an `Order` document
- To allow for an `Order` to feature a `placedBy` relationship to either an `Organization` or `User` collection
- To assign `Category` documents to `Post` documents

### Config

| Option              | Description                                                                                                                                                                   |
|---------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| **`name`** \*       | To be used as the property name when stored and retrieved from the database. [More](/docs/fields/overview#field-names)                                                        |
| **`relationTo`** \* | Provide one or many collection `slug`s to be able to assign relationships to.                                                                                                 |
| **`filterOptions`** | A query to filter which options appear in the UI and validate against. [More](#filtering-relationship-options).                                                               |
| **`hasMany`**       | Boolean when, if set to `true`, allows this field to have many relations instead of only one.                                                                                 |
| **`minRows`**       | A number for the fewest allowed items during validation when a value is present. Used with `hasMany`.                                                                         |
| **`maxRows`**       | A number for the most allowed items during validation when a value is present. Used with `hasMany`.                                                                           |
| **`maxDepth`**      | Sets a number limit on iterations of related documents to populate when queried. [Depth](/docs/getting-started/concepts#depth)                                                |
| **`label`**         | Text used as a field label in the Admin panel or an object with keys for each language.                                                                                       |
| **`unique`**        | Enforce that each entry in the Collection has a unique value for this field.                                                                                                  |
| **`validate`**      | Provide a custom validation function that will be executed on both the Admin panel and the backend. [More](/docs/fields/overview#validation)                                  |
| **`index`**         | Build an [index](/docs/database/overview) for this field to produce faster queries. Set this field to `true` if your users will perform queries on this field's data often. |
| **`saveToJWT`**     | If this field is top-level and nested in a config supporting [Authentication](/docs/authentication/config), include its data in the user JWT.                                 |
| **`hooks`**         | Provide field-based hooks to control logic for this field. [More](/docs/fields/overview#field-level-hooks)                                                                    |
| **`access`**        | Provide field-based access control to denote what users can see and do with this field's data. [More](/docs/fields/overview#field-level-access-control)                       |
| **`hidden`**        | Restrict this field's visibility from all APIs entirely. Will still be saved to the database, but will not appear in any API or the Admin panel.                              |
| **`defaultValue`**  | Provide data to be used for this field's default value. [More](/docs/fields/overview#default-values)                                                                          |
| **`localized`**     | Enable localization for this field. Requires [localization to be enabled](/docs/configuration/localization) in the Base config.                                               |
| **`required`**      | Require this field to have a value.                                                                                                                                           |
| **`admin`**         | Admin-specific configuration. See the [default field admin config](/docs/fields/overview#admin-config) for more details.                                                      |
| **`custom`**        | Extension point for adding custom data (e.g. for plugins)                                                                                                                     |

_\* An asterisk denotes that a property is required._

<Banner type="success">
  <strong>Tip:</strong>
  <br />
  The [Depth](/docs/getting-started/concepts#depth) parameter can be used to automatically populate
  related documents that are returned by the API.
</Banner>

### Admin config

In addition to the default [field admin config](/docs/fields/overview#admin-config), the Relationship field type also
allows for the following admin-specific properties:

**`isSortable`**

Set to `true` if you'd like this field to be sortable within the Admin UI using drag and drop (only works when `hasMany`
is set to `true`).

**`allowCreate`**

Set to `false` if you'd like to disable the ability to create new documents from within the relationship field (hides
the "Add new" button in the admin UI).

**`sortOptions`**

The `sortOptions` property allows you to define a default sorting order for the options within a Relationship field's
dropdown. This can be particularly useful for ensuring that the most relevant options are presented first to the user.

You can specify `sortOptions` in two ways:

**As a string:**

Provide a string to define a global default sort field for all relationship field dropdowns across different
collections. You can prefix the field name with a minus symbol ("-") to sort in descending order.

Example:

```ts
sortOptions: 'fieldName',
```

This configuration will sort all relationship field dropdowns by `"fieldName"` in ascending order.

**As an object :**

Specify an object where keys are collection slugs and values are strings representing the field names to sort by. This
allows for different sorting fields for each collection's relationship dropdown.

Example:

```ts
sortOptions: {
  "pages"
:
  "fieldName1",
    "posts"
:
  "-fieldName2",
    "categories"
:
  "fieldName3"
}
```

In this configuration:

- Dropdowns related to `pages` will be sorted by `"fieldName1"` in ascending order.
- Dropdowns for `posts` will use `"fieldName2"` for sorting in descending order (noted by the "-" prefix).
- Dropdowns associated with `categories` will sort based on `"fieldName3"` in ascending order.

Note: If `sortOptions` is not defined, the default sorting behavior of the Relationship field dropdown will be used.

### Filtering relationship options

Options can be dynamically limited by supplying a [query constraint](/docs/queries/overview), which will be used both
for validating input and filtering available relationships in the UI.

The `filterOptions` property can either be a `Where` query, or a function returning `true` to not filter, `false` to
prevent all, or a `Where` query. When using a function, it will be
called with an argument object with the following properties:

| Property      | Description                                                                          |
|---------------|--------------------------------------------------------------------------------------|
| `relationTo`  | The `relationTo` to filter against (as defined on the field)                         |
| `data`        | An object of the full collection or global document currently being edited           |
| `siblingData` | An object of the document data limited to fields within the same parent to the field |
| `id`          | The value of the collection `id`, will be `undefined` on create request              |
| `user`        | The currently authenticated user object                                              |

### Example

```ts
import { CollectionConfig } from 'payload/types'

export const ExampleCollection: CollectionConfig = {
  slug: 'example-collection',
  fields: [
    {
      name: 'purchase',
      type: 'relationship',
      relationTo: ['products', 'services'],
      filterOptions: ({ relationTo, siblingData }) => {
        // returns a Where query dynamically by the type of relationship
        if (relationTo === 'products') {
          return {
            stock: { greater_than: siblingData.quantity },
          }
        }

        if (relationTo === 'services') {
          return {
            isAvailable: { equals: true },
          }
        }
      },
    },
  ],
}
```

You can learn more about writing queries [here](/docs/queries/overview).

<Banner type="warning">
  <strong>Note:</strong>
  <br />
  When a relationship field has both <strong>filterOptions</strong> and a custom{' '}
  <strong>validate</strong> function, the api will not validate <strong>filterOptions</strong>{' '}
  unless you call the default relationship field validation function imported from{' '}
  <strong>payload/fields/validations</strong> in your validate function.
</Banner>

### How the data is saved

Given the variety of options possible within the `relationship` field type, the shape of the data needed for creating
and updating these fields can vary. The following sections will describe the variety of data shapes that can arise from
this field.

#### Has One

The most simple pattern of a relationship is to use `hasMany: false` with a `relationTo` that allows for only one type
of collection.

```ts
{
  slug: 'example-collection',
    fields
:
  [
    {
      name: 'owner', // required
      type: 'relationship', // required
      relationTo: 'users', // required
      hasMany: false,
    }
  ]
}
```

The shape of the data to save for a document with the field configured this way would be:

```json
{
  // ObjectID of the related user
  "owner": "6031ac9e1289176380734024"
}
```

When querying documents in this collection via REST API, you could query as follows:

`?where[owner][equals]=6031ac9e1289176380734024`.

#### Has One - Polymorphic

Also known as **dynamic references**, in this configuration, the `relationTo` field is an array of Collection slugs that
tells Payload which Collections are valid to reference.

```ts
{
  slug: 'example-collection',
    fields
:
  [
    {
      name: 'owner', // required
      type: 'relationship', // required
      relationTo: ['users', 'organizations'], // required
      hasMany: false,
    }
  ]
}
```

The shape of the data to save for a document with more than one relationship type would be:

```json
{
  "owner": {
    "relationTo": "organizations",
    "value": "6031ac9e1289176380734024"
  }
}
```

Here is an example for how to query documents by this data (note the difference in referencing the `owner.value`):

`?where[owner.value][equals]=6031ac9e1289176380734024`.

You can also query for documents where a field has a relationship to a specific Collection:

`?where[owners.relationTo][equals]=organizations`.

This query would return only documents that have an owner relationship to organizations.

#### Has Many

The `hasMany` tells Payload that there may be more than one collection saved to the field.

```ts
{
  slug: 'example-collection',
    fields
:
  [
    {
      name: 'owners', // required
      type: 'relationship', // required
      relationTo: 'users', // required
      hasMany: true,
    }
  ]
}
```

To save the to `hasMany` relationship field we need to send an array of IDs:

```json
{
  "owners": [
    "6031ac9e1289176380734024",
    "602c3c327b811235943ee12b"
  ]
}
```

When querying documents, the format does not change for arrays:

`?where[owners][equals]=6031ac9e1289176380734024`.

#### Has Many - Polymorphic

```ts
{
  slug: 'example-collection',
    fields
:
  [
    {
      name: 'owners', // required
      type: 'relationship', // required
      relationTo: ['users', 'organizations'], // required
      hasMany: true,
      required: true,
    }
  ]
}
```

Relationship fields with `hasMany` set to more than one kind of collections save their data as an array of objects—each
containing the Collection `slug` as the `relationTo` value, and the related document `id` for the `value`:

```json
{
  "owners": [
    {
      "relationTo": "users",
      "value": "6031ac9e1289176380734024"
    },
    {
      "relationTo": "organizations",
      "value": "602c3c327b811235943ee12b"
    }
  ]
}
```

Querying is done in the same way as the earlier Polymorphic example:

`?where[owners.value][equals]=6031ac9e1289176380734024`.

#### Querying and Filtering Polymorphic Relationships

Polymorphic and non-polymorphic relationships must be queried differently because of how the related data is stored and
may be inconsistent across different collections. Because of this, filtering polymorphic relationship fields from the
Collection List admin UI is limited to the `id` value.

For a polymorphic relationship, the response will always be an array of objects. Each object will contain
the `relationTo` and `value` properties.

The data can be queried by the related document ID:

`?where[field.value][equals]=6031ac9e1289176380734024`.

Or by the related document Collection slug:

`?where[field.relationTo][equals]=your-collection-slug`.

However, you **cannot** query on any field values within the related document.
Since we are referencing multiple collections, the field you are querying on may not exist and break the query.

<Banner type="warning">
  <strong>Note:</strong>
  <br />
  You <strong>cannot</strong> query on a field within a polymorphic relationship as you would with a non-polymorphic relationship.
</Banner>