Find a document (HTTP)
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For details about additional languages, see: |
Finds a single document in a collection using filter and sort clauses, including vector search.
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Ready to write code? See the examples for this method to get started. |
Result
Returns a dictionary representation of a document that matches the specified filter and sort clauses, or returns null if no document was found.
The fields included in the returned document depend on the subset of fields that were requested in the projection. If requested and applicable, the document will also include a $similarity key with a numeric similarity score that represents the closeness of the sort vector and the document’s vector.
Example response:
{
"data": {
"document": {
"_id": 101,
"name": "John Doe",
"$vector": [0.12, 0.52, 0.32]
}
}
}Example null response:
{
"data": {
"document": null
}
}Signature
Use the findOne command.
curl -sS -L -X POST "API_ENDPOINT/api/json/v1/KEYSPACE_NAME/COLLECTION_NAME" \
--header "Token: APPLICATION_TOKEN" \
--header "Content-Type: application/json" \
--data '{
"findOne": {
"filter": FILTER,
"sort": SORT,
"projection": PROJECTION,
}
}'Parameters
| Name | Type | Summary |
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Optional. An object that defines filter criteria using the Data API filter syntax. The method only finds documents that match the filter criteria. Filters can improve performance by reducing the number of documents that the Data API processes. You must use For a list of available filter operators and more examples, see Filter operators for collections (HTTP). Filters can use only indexed fields. If you apply selective indexing when you create a collection, you cannot reference non-indexed fields in a filter. For an example, see Use filters to find a document. |
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Optional. Sorts documents by one or more fields, or performs a vector search. You must use For more information, see Sort clauses for collections (HTTP). Sort clauses can use only indexed fields. If you apply selective indexing when you create a collection, you cannot reference non-indexed fields in sort queries. For vector searches, this parameter can use For examples, see Use sorting to find a document and Use vector search to find a document. |
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Optional. Controls which fields are included or excluded in the returned document. You must use For more information, see Projections for collections (HTTP). Default: The default projection for the collection.
All fields prefixed with For examples, see Include only specific fields in the response and Exclude specific fields from the response. |
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Optional.
The options for this operation. See Properties of |
| Name | Type | Summary |
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Examples
The following examples demonstrate how to find a document in a collection.
Use a document’s ID to find a document
All documents have a unique _id property. You can use a filter to find a document with a specific _id.
curl -sS -L -X POST "API_ENDPOINT/v1/KEYSPACE_NAME/COLLECTION_NAME" \
--header "Token: APPLICATION_TOKEN" \
--header "Content-Type: application/json" \
--data '{
"findOne": {
"filter": { "_id": "101" }
}
}'Use filters to find a document
You can use a filter to find a document that matches specific criteria.
For example, you can find a document with an is_checked_out value of false and a number_of_pages value less than 300.
For a list of available filter operators and more examples, see Filter operators for collections (HTTP).
Filters can use only indexed fields. If you apply selective indexing when you create a collection, you cannot reference non-indexed fields in a filter.
curl -sS -L -X POST "API_ENDPOINT/v1/KEYSPACE_NAME/COLLECTION_NAME" \
--header "Token: APPLICATION_TOKEN" \
--header "Content-Type: application/json" \
--data '{
"findOne": {
"filter": {"$and": [
{"is_checked_out": false},
{"number_of_pages": {"$lt": 300}}
]}
}
}'Use vector search to find a document
To find the document whose $vector value is most similar to a given vector, use a sort with the vector embeddings that you want to match. For more information, see Find data with vector search.
Vector search is only available for vector-enabled collections.
For more information, see Create a collection that can store vector embeddings and $vector in collections (HTTP).
You can provide the search vector as an array of floats, or you can use $binary to provide the search vector as a Base64-encoded string.
$binary can be more performant.
For more information about how to convert an array of floats to a Base64-encoded string, see Binary encoding of vector embeddings.
- Array of floats
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curl -sS -L -X POST "API_ENDPOINT/v1/KEYSPACE_NAME/COLLECTION_NAME" \ --header "Token: APPLICATION_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "findOne": { "sort": { "$vector": [0.08, -0.62, 0.39] } } }' - $binary
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curl -sS -L -X POST "API_ENDPOINT/v1/KEYSPACE_NAME/COLLECTION_NAME" \ --header "Token: APPLICATION_TOKEN" \ --header "Content-Type: application/json" \ --data '{ "findOne": { "sort": { "$vector": {"$binary": "PaPXCr8euFI+x64U"} } } }'
Use sorting to find a document
You can use a sort clause to sort documents by one or more fields.
For more information, see Sort clauses for collections (HTTP).
Sort clauses can use only indexed fields. If you apply selective indexing when you create a collection, you cannot reference non-indexed fields in sort queries.
curl -sS -L -X POST "API_ENDPOINT/v1/KEYSPACE_NAME/COLLECTION_NAME" \
--header "Token: APPLICATION_TOKEN" \
--header "Content-Type: application/json" \
--data '{
"findOne": {
"filter": { "metadata.language": "English" },
"sort": {
"rating": 1,
"title": -1
}
}
}'Include only specific fields in the response
To specify which fields to include or exclude in the returned document, use a projection.
All fields prefixed with $ are excluded by default and will only be returned if you include them in the projection.
_id is included by default and will always be returned unless you exclude it from the projection.
curl -sS -L -X POST "API_ENDPOINT/v1/KEYSPACE_NAME/COLLECTION_NAME" \
--header "Token: APPLICATION_TOKEN" \
--header "Content-Type: application/json" \
--data '{
"findOne": {
"filter": {"metadata.language": "English"},
"projection": {"is_checked_out": true, "title": true}
}
}'Exclude specific fields from the response
To specify which fields to include or exclude in the returned document, use a projection.
All fields prefixed with $ are excluded by default and will only be returned if you include them in the projection.
_id is included by default and will always be returned unless you exclude it from the projection.
curl -sS -L -X POST "API_ENDPOINT/v1/KEYSPACE_NAME/COLLECTION_NAME" \
--header "Token: APPLICATION_TOKEN" \
--header "Content-Type: application/json" \
--data '{
"findOne": {
"filter": {"metadata.language": "English"},
"projection": {"is_checked_out": false, "title": false}
}
}'Use filter, sort, and projection together
curl -sS -L -X POST "API_ENDPOINT/v1/KEYSPACE_NAME/COLLECTION_NAME" \
--header "Token: APPLICATION_TOKEN" \
--header "Content-Type: application/json" \
--data '{
"findOne": {
"filter": {"$and": [
{"is_checked_out": false},
{"number_of_pages": {"$lt": 300}}
]},
"sort": {
"rating": 1,
"title": -1
},
"projection": {"is_checked_out": true, "title": true}
}
}'Work with . and & in field names
You must use & to escape any . or & in field names when the field is used in a filter, sort, projection, update, or indexing clause.
Dot notation, which is used to reference nested fields, should not be escaped.
For more information, see Work with . and & in field names (HTTP).
For example, in the following document, you would use escaping like this: areas.r&&d, costs.price&.usd, and costs.price&.cad.
{
"areas": {
"r&d": true,
"design": false
},
"costs": {
"price.usd": 100,
"price.cad": 90
}
}curl -sS -L -X POST "API_ENDPOINT/v1/KEYSPACE_NAME/COLLECTION_NAME" \
--header "Token: APPLICATION_TOKEN" \
--header "Content-Type: application/json" \
--data '{
"findOne": {
"filter": {"$and": [
{"areas.r&&d": false},
{"costs.price&.usd": {"$lt": 300}}
]},
"sort": {
"costs.price&.usd": 1
},
"projection": {"areas.r&&d": true, "costs.price&.cad": true}
}
}'