Snippet Name: MongoDB_path_collision_error

Tags:

Created Date: 2025-06-16 13:12:40
Last Modified Date: 2025-05-31 10:32:17

Dependencies:

DBA Notes:

Sample Output:

Title: MongoDB path collision error
Author: user
In MongoDB, when i run this command, i get teh error below: db.inflight_part_v2.find({"child_id": null, "part_information.supplier_name": "Body Parts"}). the error is "path collision at digital_asset.document remaining portion document"

Author: ChatGPT
The error you're seeing ??? **"path collision at digital_asset.document remaining portion document"** ??? typically occurs in MongoDB when a query or projection leads to a **conflict between a field and a subfield**. In your case, MongoDB is detecting a situation where it sees both:

- A field `digital_asset.document`
- And possibly a full object `digital_asset` that also includes a `document` key

This kind of conflict confuses MongoDB???s internal document traversal logic, especially when it's traversing nested objects and arrays.

---

### Example of the Conflict:

Imagine a document like this:

```json
{
  "digital_asset": {
    "document": "abc.pdf",
    "document.title": "Some Title"
  }
}
```

Or if the document contains both:

```json
{
  "digital_asset.document": "abc.pdf",
  "digital_asset": {
    "document": {
      "title": "Some Title"
    }
  }
}
```

This creates ambiguity ??? is `digital_asset.document` a field or a nested object? **This ambiguity causes the path collision.**

---

### How to Diagnose:

1. **Run a projection to inspect the structure:**

```javascript
db.inflight_part_v2.find(
  {"child_id": null, "part_information.supplier_name": "Body Parts"},
  {"digital_asset": 1}
).limit(10).pretty()
```

This will show you what `digital_asset` looks like in some sample documents.

---

### How to Fix It:

#### Option 1: Clean or fix inconsistent document structure
- Use an aggregation pipeline to filter or transform problematic documents
- Normalize structure to avoid same-name field/subfield conflicts

#### Option 2: Avoid projecting or querying fields with ambiguous paths
If you're querying deeply nested fields like `digital_asset.document` **and** your documents also have `digital_asset` as a root-level object, use more specific queries or `$exists` checks:

```javascript
db.inflight_part_v2.find({
  "child_id": null,
  "part_information.supplier_name": "Body Parts",
  "digital_asset.document": { $exists: true }
})
```

Or explicitly filter out documents where `digital_asset.document` is not a conflict:

```javascript
db.inflight_part_v2.find({
  "child_id": null,
  "part_information.supplier_name": "Body Parts",
  "digital_asset": { $type: "object" }
})
```

---

Would you like help writing a script to find and fix those conflicting documents?