Interface FindOneOptions

If true, include the similarity score in the result via the $similarity field.

If false, do not include the similarity score in the result.

Defaults to false.

Default Value

false
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Example

const doc = await collection.findOne({}, {
  sort: {
    $vector: [.12, .52, .32],
  },
  includeSimilarity: true,
});

console.log(doc?.$similarity);
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Specifies which fields should be included/excluded in the returned documents.

If not specified, all fields are included.

When specifying a projection, it's the user's responsibility to handle the return type carefully, as the projection will, of course, affect the shape of the returned documents. It may be a good idea to cast the returned documents into a type that reflects the projection to avoid runtime errors.

Example

interface User {
  name: string;
  age: number;
}

const collection = db.collection<User>('users');

const doc = await collection.findOne({}, {
  projection: {
    _id: 0,
    name: 1,
  },
  vector: [.12, .52, .32],
  includeSimilarity: true,
}) as { name: string, $similarity: number };

// Ok
console.log(doc.name);
console.log(doc.$similarity);

// Causes type error
console.log(doc._id);
console.log(doc.age);
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The order in which to apply the update if the filter selects multiple documents.

If multiple documents match the filter, only one will be updated.

Defaults to null, where the order is not guaranteed.

Default Value

null
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An optional vector to use of the appropriate dimensionality to perform an ANN vector search on the collection to find the closest matching document.

This is purely for the user's convenience and intuitiveness—it is equivalent to setting the $vector field in the sort field itself. The two are interchangeable, but mutually exclusive.

If the sort field is already set, an error will be thrown. If you really need to use both, you can set the $vector field in the sort object directly.

Deprecated

• Prefer to use sort: { $vector: [...] } instead

Akin to FindOneOptions.vector, but for $vectorize.

Deprecated

• Prefer to use sort: { $vectorize: '...' } instead