170 lines
6.7 KiB
Plaintext
170 lines
6.7 KiB
Plaintext
---
|
|
title: Relationship Field
|
|
label: Relationship
|
|
order: 110
|
|
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>
|
|
|
|
**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. |
|
|
| **`relationTo`** * | Provide one or many collection `slug`s to be able to assign relationships to. |
|
|
| **`hasMany`** | Boolean when, if set to `true`, allows this field to have many relations instead of only one. |
|
|
| **`maxDepth`** | Sets a number limit on iterations of related documents to populate when queried. [Depth](/docs/getting-started/concepts#depth) |
|
|
| **`label`** | Used as a field label in the Admin panel and to name the generated GraphQL type. |
|
|
| **`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 a [MongoDB index](https://docs.mongodb.com/manual/indexes/) 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. |
|
|
| **`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. |
|
|
|
|
*\* An asterisk denotes that a property is required.*
|
|
|
|
<Banner type="success">
|
|
<strong>Tip:</strong><br/>
|
|
The <a href="/docs/getting-started/concepts#depth">Depth</a> parameter can be used to automatically populate related documents that are returned by the API.
|
|
</Banner>
|
|
|
|
### Example Patterns
|
|
Given the variety of options possible for relationships the shape of the data needed for creating and updating collections can vary. When `hasMany` is true, the field data is an array. When `relationTo` is an array, an object with `relationTo` property for the collection slug and `value` for the ID.
|
|
|
|
<Banner>
|
|
The Payload admin panel will send the correct format of form data needed, the below examples are most useful for understanding Local API operations or saving to the database directly.
|
|
</Banner>
|
|
|
|
#### 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.
|
|
```js
|
|
{
|
|
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
|
|
{
|
|
"owner": "6031ac9e1289176380734024"
|
|
}
|
|
```
|
|
|
|
When making a `GET` request to the api, the query params in the URL would be:
|
|
`?where[owner][equals]=6031ac9e1289176380734024`.
|
|
|
|
#### Has One - Polymorphic
|
|
Also known as **dynamic references**, in this configuration the `relationTo` field is an array of slugs to tell Payload what the collections to reference are.
|
|
```js
|
|
{
|
|
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"
|
|
}
|
|
}
|
|
```
|
|
|
|
When making a `GET` request to the api, note the difference in referencing the `owner.value`:
|
|
`?where[owner.value][equals]=6031ac9e1289176380734024`.
|
|
|
|
You can also query for collections where a field has a relationship to a specific slug: `?where[owners.relationTo][equals]=organizations` which 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.
|
|
```js
|
|
{
|
|
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 making a `GET` request to the api, the format does not change for arrays:
|
|
`?where[owners][equals]=6031ac9e1289176380734024`.
|
|
|
|
#### Has Many - Polymorphic
|
|
```js
|
|
{
|
|
slug: 'example-collection',
|
|
fields: [
|
|
{
|
|
name: 'owners', // required
|
|
type: 'relationship', // required
|
|
relationTo: ['users', 'organizations'], // required
|
|
hasMany: true,
|
|
required: true,
|
|
}
|
|
]
|
|
}
|
|
```
|
|
|
|
To save to `hasMany` relationship of more than one kind of collections, use an array of objects having the collection `slug` as the `relationTo` and the related document `id` for the `value`:
|
|
```json
|
|
{
|
|
"owners": [
|
|
{
|
|
"relationTo": "users",
|
|
"value": "6031ac9e1289176380734024"
|
|
}, {
|
|
"relationTo": "organizations",
|
|
"value": "602c3c327b811235943ee12b"
|
|
}
|
|
]
|
|
}
|
|
```
|
|
|
|
When making a `GET` request to the api, in the same way as the earlier polymorphic:
|
|
`?where[owners.value][equals]=6031ac9e1289176380734024`.
|