如何在Parse Server中获取指定用户关联数据？REST API异常求助

Hey Dave, let's break down why you might be getting empty arrays when querying your Interest class—especially since your User class queries work fine. Here are the most common culprits to check:

1. Incorrect Field Type for User Association #

First, double-check the field in your Interest class that links to the User object. If you stored the user's objectId as a plain String instead of a Pointer type, your query won't match any records.

• Head to your Parse Dashboard, navigate to the Interest class, and verify the field (e.g., user) is set to Pointer<_User>, not String.
• If it's a string field, you'll need to either:
  • Update existing records to use Pointer values, or
  • Adjust your query to match the string directly (e.g., where={"userId":"USER_OBJECT_ID"} instead of Pointer syntax).

2. Malformed Query Parameters #

Parse's REST API requires precise syntax for Pointer-based queries. A tiny mistake here will return no results. Make sure your where clause follows this exact structure:

{
  "where": {
    "user": {
      "__type": "Pointer",
      "className": "_User",
      "objectId": "YOUR_TARGET_USER_ID"
    }
  }
}

• Critical note: The className must be _User (with the underscore) for the built-in User class—using User without the underscore will fail.
• Example curl request to test:

curl -X GET "https://your-parse-server-url/parse/classes/Interest" \
  -H "X-Parse-Application-Id: YOUR_APP_ID" \
  -H "X-Parse-REST-API-Key: YOUR_REST_KEY" \
  -H "Content-Type: application/json" \
  -d '{"where":{"user":{"__type":"Pointer","className":"_User","objectId":"abc123"}}}'

3. Permission or ACL Restrictions #

Parse's default permissions might be blocking your query, even if the data exists:

• Class-level permissions: Check the Interest class's permissions in the Parse Dashboard. Ensure the "Get" permission is enabled for the role/user making the request (e.g., "Public" if you're querying without a user session).
• Record-level ACLs: If individual Interest records have ACLs set, make sure the requesting user (or public access) has read permissions. For example, if an Interest record's ACL only allows the linked user to read it, you'll need to include a valid session token in your request headers:

  -H "X-Parse-Session-Token: USER_SESSION_TOKEN"
  

4. No Matching Data Exists (Double-Check the Dashboard) #

Before assuming it's a query bug, confirm the data actually exists:

• In the Parse Dashboard, go to the Interest class and use the filter to search for records linked to your target user's objectId.
• If no records show up here, the issue is that the关联数据 wasn't saved correctly in the first place—not the query itself.

5. Case Sensitivity Issues #

Parse class and field names are case-sensitive:

• Ensure you're using the exact class name (e.g., Interest vs. interest) in your request URL.
• Double-check the field name linking to User (e.g., user vs. User) matches what's defined in the dashboard.

Start with verifying the data exists in the dashboard, then work through the field type and query syntax—those are the most frequent fixes for this issue. Let me know if any of these steps resolve it!

内容的提问来源于stack exchange，提问作者Dave Gavigan