---
title: About the parentId property
slug: '57'
canonical_url: https://docs.coveo.com/en/57/
collection: index-content
source_format: adoc
---
# About the parentId property
When adding or updating [items](https://docs.coveo.com/en/210/) in a Push [source](https://docs.coveo.com/en/246/), you can use the `parentId` property to [define parent-child relationships](#define-parent-child-relationships) between those items.
Doing so populates a set of [fields](https://docs.coveo.com/en/200/) that you can [leverage in nested queries](#leverage-parentid-generated-fields-in-nested-queries).

> **Note**
>
> Using the `parentId` property doesn't populate any field that would allow you to load the parent of a folded collection.
> 
> Therefore, to [request and render folded results](https://docs.coveo.com/en/428/) from a Push source, you should rather define your parent-child relationships by sending metadata to populate the [standard folding fields](https://docs.coveo.com/en/2718/) in your index (that is, `@foldingcollection`, `@foldingparent`, and `@foldingchild`).

## Define parent-child relationships

You can use the `parentId` property to define simple parent-child relationships between items in a Push source.

To do so:

* If an item is the _parent_ of a relationship, set its `parentId` to its own `documentId`.
* If an item is a _child_ in a relationship, set its `parentId` to the `documentId` of its parent.

Specifying a `parentId` when pushing an item always populates the `@topparentid` field for that item.

If the `parentId` value differs from the `documentId` value of the pushed item, the `@attachmentparentid` field gets populated as well.

### Example

In a Push source, you want to define simple parent-child relationships between items representing directors and movies.

. You [create a file container](https://docs.coveo.com/en/43/).

```http
POST https://api.cloud.coveo.com/push/v1/organizations/coveomovieorganization/files HTTP/1.1
​
Authorization: Bearer **********-****-****-****-************
Accept: application/json
```

. You [upload a batch of items into the file container](https://docs.coveo.com/en/90#step-2-upload-the-content-update-into-the-file-container) you previously created, using the `parentId` property to define the desired relationships.

```http
PUT https://coveo-nprod-customerdata.s3.amazonaws.com/proda/blobstore/coveomovieorganization/2a65f989-2371-4dc6-b6aa-198b5b88ff29?x-amz-security-token=FQoGZXIvYXdzEB8aDL37SykFY6%2FzbYBDPCLlAQmJ0nWbMK0Bxq3wcGnEq1bPcDGsP7dTaKkuuAPOA7LaNZhosW3d8ybg14N8o9OAaUS%2BoQ9Y1oZROmh%2BHZbP7krJAlDRUQS2NtrGxUh20h3GInWxTM5CZ86p5een1Gzsk%2FuCrKCXpqGFJZ1UwEFkEGtj2M2l%2F3eOhfPd6ga9%2F51NgHQPXRc4z%2F5NLiEfWlv%2FxzLZHrtznCjj8fi77QKcLkzO9kiLOtWtZVxmoMg4jVZYwZuOdfRqAVEzaWIsP8lQ2O5AWTwD5O8HKjmtO6v%2FZiV9diYDx7Z7WtrKJg1v2upFHhxljxUo6%2BCG2wU%3D&AWSAccessKeyId=ASIAYKDJLZIT5VRAMAJE&Expires=1533134515&Signature=fyZW7rDLYWSt%2B6rRTPaQPc72uUY%3D HTTP/1.1
​
Content-Type: application/octet-stream
x-amz-server-side-encryption: "AES256"
```

Request body:

```json
{
  "addOrUpdate": [
    {
      "title": "Edgar Wright",
      "data": "...",
      "documentId": "file://directors/edgar-wright.txt",
      "parentId": "file://directors/edgar-wright.txt",
      "documenttype": "Director"
    },
    {
      "title": "The World's End",
      "data": "...",
      "documentId": "file://movies/the-world-s-end.txt",
      "parentId": "file://directors/edgar-wright.txt",
      "documenttype": "Movie"
    },
    {
      "title": "Baby Driver",
      "data": "...",
      "documentId": "file://movies/baby-driver.txt",
      "parentId": "file://directors/edgar-wright.txt",
      "documenttype": "Movie"
    },
    {
      "title": "Stanley Kubrick",
      "data": "...",
      "documentId": "file://directors/stanley-kubrick.txt",
      "parentId": "file://directors/stanley-kubrick.txt",
      "documenttype": "Director"
    },
    {
      "title": "The Shining",
      "data": "...",
      "documentId": "file://movies/the-shining.txt",
      "parentId": "file://directors/stanley-kubrick.txt",
      "documenttype": "Movie"
    }
  ],
  "delete": []
}
```

. You [push the file container](https://docs.coveo.com/en/90#step-3-push-the-file-container-into-a-push-source) to your source.

```http
POST https://api.cloud.coveo.com/push/v1/organizations/coveomovieorganization/sources/vzievcixq66qq5q6xulpy32dqi-coveomovieorganization/documents/batch?fileId=b5e8767e-8f0d-4a89-9095-1127915c89c7 HTTP/1.1
​
Authorization: Bearer **********-****-****-****-************
Accept: application/json
```

When the indexing pipeline finishes processing the batch, the `@topparentid` and `@attachmentparentid` fields are populated as follows:
|===
| Item title | Document type | `@topparentid` value | `@attachmentparentid` value

| Edgar Wright
| Director
| 32345
| N/A

| Stanley Kubrick
| Director
| 32338
| N/A

| The World's End
| Movie
| 32345
| 32345

| Baby Driver
| Movie
| 32345
| 32345

| The Shining
| Movie
| 32338
| 32338
|===

## Leverage parentId-generated fields in nested queries

The `@topparentid` and `@attachmentparentid` numeric fields can be useful in [nested queries](https://docs.coveo.com/en/220/).

> **Leading practice**
>
> Ensure that the [**Use cache for numeric queries** option](https://docs.coveo.com/en/1833#use-cache-for-nested-queries) is enabled for nested query fields.
> Doing so will allow for quicker numeric operations (for example, comparing integers), making query executions faster.

### Example

When querying items from the Push source described in the [Defining parent-child relationships](#define-parent-child-relationships) example, you could use the following nested query to retrieve all movies by director Edgar Wright:

```text
[[@attachmentparentid] @topparentid==32345]
```

**Query response excerpt**

```json
{
  "totalCount": 2,
  ...
  "results": [
    {
      "title": "Baby Driver",
      "uri": "file://movies/baby-driver.txt",
      ...
      "raw": {
        ...
        "attachmentparentid": 32345,
        "topparentid": 32345,
        ...
      }
      ...
    },
    {
      "title": "The World's End",
      "uri": "file://movies/the-world-s-end.txt",
      ...
      "raw": {
        ...
        "attachmentparentid": 32345,
        "topparentid": 32345,
        ...
      }
      ...
    }
  ]
}
```