Find a document

Finds a single document in a collection using filter and sort clauses, including vector search.

Ready to write code? See the examples for this method to get started. If you are new to the Data API, check out the quickstart.

Result

Python
TypeScript
Java
curl

Returns a dictionary representation of a document that matches the specified filter and sort clauses, or returns None 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:

{'_id': 101, 'name': 'John Doe', '$vector': [0.12, 0.52, 0.32]}

Returns a promise that resolves to a document that matches the specified filter and sort clauses, or to null if no document was found.

Example response:

{'_id': 101, 'name': 'John Doe', '$vector': [0.12, 0.52, 0.32]}

Returns a document that matches the specified filter and sort clauses (Optional<T>), or returns Optional.empty() if no document was found.

Returns a dictionary representation of a document that matches the specified filter and sort clauses, or returns null if no document was found.

Example response:

{
  "data": {
    "document": {
      "_id": 101,
      "name": "John Doe",
      "$vector": [0.12, 0.52, 0.32]
    }
  }
}

Example null response:

{
  "data": {
    "document": null
  }
}

Parameters

Python
TypeScript
Java
curl

Use the find_one method, which belongs to the astrapy.Collection class.

Method signature

find_one(
  filter: Dict[str, Any],
  *,
  projection: Dict[str, bool],
  include_similarity: bool,
  sort: Dict[str, Any],
  general_method_timeout_ms: int,
  request_timeout_ms: int,
  timeout_ms: int,
) -> Dict[str, Any]

Name Type Summary

Name	Type	Summary
`filter`	`Dict[str, Any]`	Optional. An object that defines filter criteria using the Data API filter syntax. The method only finds documents that match the filter criteria. You must use `&` to escape any `.` or `&` in field names in the filter clause. You cannot use `&` to escape any other characters. For a list of available filter operators and more examples, see Filter operators for collections. 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.
`projection`	`Dict[str, bool]`	Optional. Controls which fields are included or excluded in the returned document. You must use `&` to escape any `.` or `&` in field names in the projection clause. You cannot use `&` to escape any other characters. For more information, see Projections for collections. Default: The default projection for the collection. All fields prefixed with `$` are excluded by default and will only be returned if you include them in the projection. `_id` is included by default and will always be returned unless you exclude them from the projection.
`include_similarity`	`bool`	Optional. Whether to include a `$similarity` property in the response. The `$similarity` value represents the closeness of the sort vector and the document’s vector. This parameter only applies if you use a vector search. Default: False
`sort`	`Dict[str, Any]`	Optional. Sorts documents by one or more fields, or performs a vector search. You must use `&` to escape any `.` or `&` in field names in the sort clause. You cannot use `&` to escape any other characters. For more information, see Sort clauses for collections. Sort clauses can use only indexed fields. If you apply selective indexing when you create a collection, you cannot reference non-indexed fields in sort queries. For vector searches, this parameter can use `$vector`.
`general_method_timeout_ms`	`int`	Optional. The maximum time, in milliseconds, that the client should wait for the underlying HTTP request. Default: The default value for the collection. This default is 30 seconds unless you specified a different default when you initialized the `Collection` or `DataAPIClient` object. For more information, see Timeout options.
`request_timeout_ms`	`int`	Optional. An alias for `general_method_timeout_ms`. Since this method issues a single HTTP request, `general_method_timeout_ms` and `request_timeout_ms` are equivalent.
`timeout_ms`	`int`	Optional. An alias for `general_method_timeout_ms`.

filter

Dict[str, Any]

Optional. An object that defines filter criteria using the Data API filter syntax. The method only finds documents that match the filter criteria.

You must use & to escape any . or & in field names in the filter clause. You cannot use & to escape any other characters.

For a list of available filter operators and more examples, see Filter operators for collections.

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.

projection

Dict[str, bool]

Optional. Controls which fields are included or excluded in the returned document.

You must use & to escape any . or & in field names in the projection clause. You cannot use & to escape any other characters.

For more information, see Projections for collections.

Default: The default projection for the collection. 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 them from the projection.

include_similarity

bool

Optional. Whether to include a $similarity property in the response. The $similarity value represents the closeness of the sort vector and the document’s vector.

This parameter only applies if you use a vector search.

Default: False

sort

Dict[str, Any]

Optional. Sorts documents by one or more fields, or performs a vector search.

You must use & to escape any . or & in field names in the sort clause. You cannot use & to escape any other characters.

For more information, see Sort clauses for collections.

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 $vector.

general_method_timeout_ms

int

Optional. The maximum time, in milliseconds, that the client should wait for the underlying HTTP request.

Default: The default value for the collection. This default is 30 seconds unless you specified a different default when you initialized the Collection or DataAPIClient object. For more information, see Timeout options.

request_timeout_ms

int

Optional. An alias for general_method_timeout_ms. Since this method issues a single HTTP request, general_method_timeout_ms and request_timeout_ms are equivalent.

timeout_ms

int

Optional. An alias for general_method_timeout_ms.

Use the findOne method, which belongs to the Collection class.

Method signature

async findOne(
  filter: CollectionFilter<Schema>,
  options?: {
    sort?: Sort,
    projection?: Projection,
    includeSimilarity?: boolean,
    timeout?: number | TimeoutDescriptor,
  },
): Schema | null

Name Type Summary

Name	Type	Summary
`filter`	`CollectionFilter<Schema>`	An object that defines filter criteria using the Data API filter syntax. The method only finds documents that match the filter criteria. You must use `&` to escape any `.` or `&` in field names in the filter clause. You cannot use `&` to escape any other characters. For a list of available filter operators and more examples, see Filter operators for collections. 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.
`options`	`CollectionFindOneOptions`	Optional. The options for this operation. See Properties of `options` for more details.

filter

CollectionFilter<Schema>

An object that defines filter criteria using the Data API filter syntax. The method only finds documents that match the filter criteria.

You must use & to escape any . or & in field names in the filter clause. You cannot use & to escape any other characters.

For a list of available filter operators and more examples, see Filter operators for collections.

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.

options

CollectionFindOneOptions

Optional. The options for this operation. See Properties of options for more details.

Properties of `options`
Name	Type	Summary
`projection`	`Projection`	Optional. Controls which fields are included or excluded in the returned document. You must use `&` to escape any `.` or `&` in field names in the projection clause. You cannot use `&` to escape any other characters. For more information, see Projections for collections. Default: The default projection for the collection. All fields prefixed with `$` are excluded by default and will only be returned if you include them in the projection. `_id` is included by default and will always be returned unless you exclude them from the projection.
`includeSimilarity`	`boolean`	Optional. Whether to include a `$similarity` property in the response. The `$similarity` value represents the closeness of the sort vector and the document’s vector. This parameter only applies if you use a vector search. Default: False
`sort`	`Sort`	Optional. Sorts documents by one or more fields, or performs a vector search. You must use `&` to escape any `.` or `&` in field names in the sort clause. You cannot use `&` to escape any other characters. For more information, see Sort clauses for collections. Sort clauses can use only indexed fields. If you apply selective indexing when you create a collection, you cannot reference non-indexed fields in sort queries. For vector searches, this parameter can use `$vector`.
`timeout`	`number` \| `TimeoutDescriptor`	Optional. The timeout(s) to apply to this method. You can specify `requestTimeoutMs` and `generalMethodTimeoutMs`. Since this method issues a single HTTP request, these timeouts are equivalent. Details about the `timeout` parameter The `TimeoutDescriptor` object can contain these properties: `requestTimeoutMs` (`number`): The maximum time, in milliseconds, that the client should wait for each underlying HTTP request. Default: The default value for the collection. This default is 10 seconds unless you specified a different default when you initialized the `Collection` or `DataAPIClient` object. `generalMethodTimeoutMs` (`number`): The maximum time, in milliseconds, that the whole operation can take. Since this method issues a single HTTP request, `generalMethodTimeoutMs` and `requestTimeoutMs` are equivalent. If you specify both, the minimum of the two will be used. Default: The default value for the collection. This default is 30 seconds unless you specified a different default when you initialized the `Collection` or `DataAPIClient` object. If you specify a number instead of a `TimeoutDescriptor` object, that number will be applied to both `requestTimeoutMs` and `generalMethodTimeoutMs`.

Use the findOne method, which belongs to the com.datastax.astra.client.Collection class.

Method signature

Optional<T> findOne(Filter filter)

Optional<T> findOne(
  Filter filter,
  CollectionFindOneOptions options
)

Optional<T> findOne(CollectionFindOneOptions options)

Name Type Summary

Name	Type	Summary
`filter`	`Filter`	An object that defines filter criteria using the Data API filter syntax. The method only finds documents that match the filter criteria. You must use `&` to escape any `.` or `&` in field names in the filter clause. You cannot use `&` to escape any other characters. For a list of available filter operators and more examples, see Filter operators for collections. 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.
`options`	`CollectionFindOneOptions`	Optional. The options for this operation. See Methods of the `CollectionFindOneOptions` class for more details.

filter

Filter

An object that defines filter criteria using the Data API filter syntax. The method only finds documents that match the filter criteria.

You must use & to escape any . or & in field names in the filter clause. You cannot use & to escape any other characters.

For a list of available filter operators and more examples, see Filter operators for collections.

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.

options

CollectionFindOneOptions

Optional. The options for this operation. See Methods of the CollectionFindOneOptions class for more details.

Methods of the `CollectionFindOneOptions` class
Method	Parameters	Summary
`sort()`	`float[] \| String \| Sort \| Map<String, Object>`	Optional. Sorts documents by one or more fields, or performs a vector search. You must use `&` to escape any `.` or `&` in field names in the sort clause. You cannot use `&` to escape any other characters. For more information, see Sort clauses for collections. 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 `$vector`.
`projection()`	`Projection`	Optional. Controls which fields are included or excluded in the returned document. You must use `&` to escape any `.` or `&` in field names in the projection clause. You cannot use `&` to escape any other characters. For more information, see Projections for collections. Default: The default projection for the collection. All fields prefixed with `$` 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 them from the projection.
`includeSimilarity()`	`boolean`	Optional. Whether to include a `$similarity` property in the response. The `$similarity` value represents the closeness of the sort vector and the document’s vector. This parameter only applies if you use a vector search. Default: False

Use the findOne command.

Command signature

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,
    "options": {
      "includeSimilarity": BOOLEAN
    }
  }
}'

Name Type Summary

Name	Type	Summary
`filter`	`object`	Optional. An object that defines filter criteria using the Data API filter syntax. The method only finds documents that match the filter criteria. You must use `&` to escape any `.` or `&` in field names in the filter clause. You cannot use `&` to escape any other characters. For a list of available filter operators and more examples, see Filter operators for collections. 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.
`sort`	`object`	Optional. Sorts documents by one or more fields, or performs a vector search. You must use `&` to escape any `.` or `&` in field names in the sort clause. You cannot use `&` to escape any other characters. For more information, see Sort clauses for collections. 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 `$vector`.
`projection`	`object`	Optional. Controls which fields are included or excluded in the returned document. You must use `&` to escape any `.` or `&` in field names in the projection clause. You cannot use `&` to escape any other characters. For more information, see Projections for collections. Default: The default projection for the collection. All fields prefixed with `$` 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 them from the projection.
`options`	`object`	Optional. The options for this operation. See Properties of `options` for more details.

filter

object

Optional. An object that defines filter criteria using the Data API filter syntax. The method only finds documents that match the filter criteria.

You must use & to escape any . or & in field names in the filter clause. You cannot use & to escape any other characters.

For a list of available filter operators and more examples, see Filter operators for collections.

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.

sort

object

Optional. Sorts documents by one or more fields, or performs a vector search.

You must use & to escape any . or & in field names in the sort clause. You cannot use & to escape any other characters.

For more information, see Sort clauses for collections.

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 $vector.

projection

object

Optional. Controls which fields are included or excluded in the returned document.

You must use & to escape any . or & in field names in the projection clause. You cannot use & to escape any other characters.

For more information, see Projections for collections.

options

object

Optional. The options for this operation. See Properties of options for more details.

Properties of `options`
Name	Type	Summary
`includeSimilarity`	`boolean`	Optional. Whether to include a `$similarity` property in the response. The `$similarity` value represents the closeness of the sort vector and the document’s vector. This parameter only applies if you use a vector search. Default: False

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.

Python
TypeScript
Java
curl

from astrapy import DataAPIClient
from astrapy.authentication import UsernamePasswordTokenProvider
from astrapy.constants import Environment

# Get an existing collection
client = DataAPIClient(environment=Environment.HCD)
database = client.get_database(
    "API_ENDPOINT",
    token=UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
)
collection = database.get_collection(
    "COLLECTION_NAME", keyspace="KEYSPACE_NAME"
)

# Find a document
result = collection.find_one({"_id": 101})

print(result)

import {
  DataAPIClient,
  UsernamePasswordTokenProvider,
} from "@datastax/astra-db-ts";

// Get an existing collection
const client = new DataAPIClient({ environment: "hcd" });
const database = client.db("API_ENDPOINT", {
  token: new UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
});
const collection = database.collection("COLLECTION_NAME", {
  keyspace: "KEYSPACE_NAME",
});

// Find a document
(async function () {
  const result = await collection.findOne({ _id: "101" });

  console.log(result);
})();

import com.datastax.astra.client.DataAPIClient;
import com.datastax.astra.client.DataAPIClients;
import com.datastax.astra.client.collections.Collection;
import com.datastax.astra.client.collections.definition.documents.Document;
import com.datastax.astra.client.core.query.Filter;
import com.datastax.astra.client.core.query.Filters;
import com.datastax.astra.client.databases.Database;
import java.util.Optional;

public class Example {

  public static void main(String[] args) {
    // Get an existing collection
    DataAPIClient client = DataAPIClients.clientHCD("USERNAME", "PASSWORD");
    Database database = client.getDatabase("API_ENDPOINT", "KEYSPACE_NAME");
    Collection<Document> collection = database.getCollection("COLLECTION_NAME");

    // Find a document
    Filter filter = Filters.eq("_id", "101");
    Optional<Document> result = collection.findOne(filter);
    System.out.println(result);
  }
}

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.

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.

Python
TypeScript
Java
curl

from astrapy import DataAPIClient
from astrapy.authentication import UsernamePasswordTokenProvider
from astrapy.constants import Environment

# Get an existing collection
client = DataAPIClient(environment=Environment.HCD)
database = client.get_database(
    "API_ENDPOINT",
    token=UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
)
collection = database.get_collection(
    "COLLECTION_NAME", keyspace="KEYSPACE_NAME"
)

# Find a document
result = collection.find_one(
    {
        "$and": [
            {"is_checked_out": False},
            {"number_of_pages": {"$lt": 300}},
        ]
    }
)

print(result)

import {
  DataAPIClient,
  UsernamePasswordTokenProvider,
} from "@datastax/astra-db-ts";

// Get an existing collection
const client = new DataAPIClient({ environment: "hcd" });
const database = client.db("API_ENDPOINT", {
  token: new UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
});
const collection = database.collection("COLLECTION_NAME", {
  keyspace: "KEYSPACE_NAME",
});

// Find a document
(async function () {
  const result = await collection.findOne({
    $and: [{ is_checked_out: false }, { number_of_pages: { $lt: 300 } }],
  });

  console.log(result);
})();

import com.datastax.astra.client.DataAPIClient;
import com.datastax.astra.client.DataAPIClients;
import com.datastax.astra.client.collections.Collection;
import com.datastax.astra.client.collections.definition.documents.Document;
import com.datastax.astra.client.core.query.Filter;
import com.datastax.astra.client.core.query.Filters;
import com.datastax.astra.client.databases.Database;
import java.util.Optional;

public class Example {

  public static void main(String[] args) {
    // Get an existing collection
    DataAPIClient client = DataAPIClients.clientHCD("USERNAME", "PASSWORD");
    Database database = client.getDatabase("API_ENDPOINT", "KEYSPACE_NAME");
    Collection<Document> collection = database.getCollection("COLLECTION_NAME");

    // Find a document
    Filter filter =
        Filters.and(Filters.eq("is_checked_out", false), Filters.lt("number_of_pages", 300));

    Optional<Document> result = collection.findOne(filter);

    System.out.println(result);
  }
}

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.

Python
TypeScript
Java
curl

from astrapy import DataAPIClient
from astrapy.authentication import UsernamePasswordTokenProvider
from astrapy.constants import Environment

# Get an existing collection
client = DataAPIClient(environment=Environment.HCD)
database = client.get_database(
    "API_ENDPOINT",
    token=UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
)
collection = database.get_collection(
    "COLLECTION_NAME", keyspace="KEYSPACE_NAME"
)

# Find a document
result = collection.find_one({}, sort={"$vector": [0.12, -0.46, 0.35, 0.52, -0.32]})

print(result)

import {
  DataAPIClient,
  UsernamePasswordTokenProvider,
} from "@datastax/astra-db-ts";

// Get an existing collection
const client = new DataAPIClient({ environment: "hcd" });
const database = client.db("API_ENDPOINT", {
  token: new UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
});
const collection = database.collection("COLLECTION_NAME", {
  keyspace: "KEYSPACE_NAME",
});

// Find a document
(async function () {
  const result = await collection.findOne(
    {},
    { sort: { $vector: [0.12, -0.46, 0.35, 0.52, -0.32] } },
  );

  console.log(result);
})();

import com.datastax.astra.client.DataAPIClient;
import com.datastax.astra.client.DataAPIClients;
import com.datastax.astra.client.collections.Collection;
import com.datastax.astra.client.collections.commands.options.CollectionFindOneOptions;
import com.datastax.astra.client.collections.definition.documents.Document;
import com.datastax.astra.client.core.query.Sort;
import com.datastax.astra.client.databases.Database;
import java.util.Optional;

public class Example {

  public static void main(String[] args) {
    // Get an existing collection
    DataAPIClient client = DataAPIClients.clientHCD("USERNAME", "PASSWORD");
    Database database = client.getDatabase("API_ENDPOINT", "KEYSPACE_NAME");
    Collection<Document> collection = database.getCollection("COLLECTION_NAME");

    // Find a document
    CollectionFindOneOptions options =
        new CollectionFindOneOptions()
            .sort(Sort.vector(new float[] {0.12f, -0.46f, 0.35f, 0.52f, -0.32f}));
    Optional<Document> result = collection.findOne(options);
    System.out.println(result);
  }
}

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.

Array of floats
$binary

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": [0.12, -0.46, 0.35, 0.52, -0.32] }
  }
}'

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": "PfXCjz8FHrg+o9cK"} }
  }
}'

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.

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.

Python
TypeScript
Java
curl

from astrapy import DataAPIClient
from astrapy.authentication import UsernamePasswordTokenProvider
from astrapy.constants import Environment
from astrapy.constants import SortMode

# Get an existing collection
client = DataAPIClient(environment=Environment.HCD)
database = client.get_database(
    "API_ENDPOINT",
    token=UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
)
collection = database.get_collection(
    "COLLECTION_NAME", keyspace="KEYSPACE_NAME"
)

# Find a document
result = collection.find_one(
    {"metadata.language": "English"},
    sort={
        "rating": SortMode.ASCENDING,
        "title": SortMode.DESCENDING,
    },
)

print(result)

import {
  DataAPIClient,
  UsernamePasswordTokenProvider,
} from "@datastax/astra-db-ts";

// Get an existing collection
const client = new DataAPIClient({ environment: "hcd" });
const database = client.db("API_ENDPOINT", {
  token: new UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
});
const collection = database.collection("COLLECTION_NAME", {
  keyspace: "KEYSPACE_NAME",
});

// Find a document
(async function () {
  const result = await collection.findOne(
    { "metadata.language": "English" },
    {
      sort: {
        rating: 1, // ascending
        title: -1, // descending
      },
    },
  );

  console.log(result);
})();

import com.datastax.astra.client.DataAPIClient;
import com.datastax.astra.client.DataAPIClients;
import com.datastax.astra.client.collections.Collection;
import com.datastax.astra.client.collections.commands.options.CollectionFindOneOptions;
import com.datastax.astra.client.collections.definition.documents.Document;
import com.datastax.astra.client.core.query.Filter;
import com.datastax.astra.client.core.query.Filters;
import com.datastax.astra.client.core.query.Sort;
import com.datastax.astra.client.databases.Database;
import java.util.Optional;

public class Example {

  public static void main(String[] args) {
    // Get an existing collection
    DataAPIClient client = DataAPIClients.clientHCD("USERNAME", "PASSWORD");
    Database database = client.getDatabase("API_ENDPOINT", "KEYSPACE_NAME");
    Collection<Document> collection = database.getCollection("COLLECTION_NAME");

    // Find a document
    Filter filter = Filters.eq("metadata.language", "English");
    CollectionFindOneOptions options =
        new CollectionFindOneOptions().sort(Sort.ascending("rating"), Sort.descending("title"));
    Optional<Document> result = collection.findOne(filter, options);
    System.out.println(result);
  }
}

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 them from the projection.

Python
TypeScript
Java
curl

from astrapy import DataAPIClient
from astrapy.authentication import UsernamePasswordTokenProvider
from astrapy.constants import Environment

# Get an existing collection
client = DataAPIClient(environment=Environment.HCD)
database = client.get_database(
    "API_ENDPOINT",
    token=UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
)
collection = database.get_collection(
    "COLLECTION_NAME", keyspace="KEYSPACE_NAME"
)

# Find a document
result = collection.find_one(
    {"metadata.language": "English"}, projection={"is_checked_out": True, "title": True}
)

print(result)

import {
  DataAPIClient,
  UsernamePasswordTokenProvider,
} from "@datastax/astra-db-ts";

// Get an existing collection
const client = new DataAPIClient({ environment: "hcd" });
const database = client.db("API_ENDPOINT", {
  token: new UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
});
const collection = database.collection("COLLECTION_NAME", {
  keyspace: "KEYSPACE_NAME",
});

// Find a document
(async function () {
  const result = await collection.findOne(
    { "metadata.language": "English" },
    { projection: { is_checked_out: true, title: true } },
  );

  console.log(result);
})();

import com.datastax.astra.client.DataAPIClient;
import com.datastax.astra.client.DataAPIClients;
import com.datastax.astra.client.collections.Collection;
import com.datastax.astra.client.collections.commands.options.CollectionFindOneOptions;
import com.datastax.astra.client.collections.definition.documents.Document;
import com.datastax.astra.client.core.query.Filter;
import com.datastax.astra.client.core.query.Filters;
import com.datastax.astra.client.core.query.Projection;
import com.datastax.astra.client.databases.Database;
import java.util.Optional;

public class Example {

  public static void main(String[] args) {
    // Get an existing collection
    DataAPIClient client = DataAPIClients.clientHCD("USERNAME", "PASSWORD");
    Database database = client.getDatabase("API_ENDPOINT", "KEYSPACE_NAME");
    Collection<Document> collection = database.getCollection("COLLECTION_NAME");

    // Find a document
    Filter filter = Filters.eq("metadata.language", "English");
    CollectionFindOneOptions options =
        new CollectionFindOneOptions().projection(Projection.include("is_checked_out", "title"));
    Optional<Document> result = collection.findOne(filter, options);
    System.out.println(result);
  }
}

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.

Python
TypeScript
Java
curl

from astrapy import DataAPIClient
from astrapy.authentication import UsernamePasswordTokenProvider
from astrapy.constants import Environment

# Get an existing collection
client = DataAPIClient(environment=Environment.HCD)
database = client.get_database(
    "API_ENDPOINT",
    token=UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
)
collection = database.get_collection(
    "COLLECTION_NAME", keyspace="KEYSPACE_NAME"
)

# Find a document
result = collection.find_one(
    {"metadata.language": "English"},
    projection={"is_checked_out": False, "title": False},
)

print(result)

import {
  DataAPIClient,
  UsernamePasswordTokenProvider,
} from "@datastax/astra-db-ts";

// Get an existing collection
const client = new DataAPIClient({ environment: "hcd" });
const database = client.db("API_ENDPOINT", {
  token: new UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
});
const collection = database.collection("COLLECTION_NAME", {
  keyspace: "KEYSPACE_NAME",
});

// Find a document
(async function () {
  const result = await collection.findOne(
    { "metadata.language": "English" },
    { projection: { is_checked_out: false, title: false } },
  );

  console.log(result);
})();

import com.datastax.astra.client.DataAPIClient;
import com.datastax.astra.client.DataAPIClients;
import com.datastax.astra.client.collections.Collection;
import com.datastax.astra.client.collections.commands.options.CollectionFindOneOptions;
import com.datastax.astra.client.collections.definition.documents.Document;
import com.datastax.astra.client.core.query.Filter;
import com.datastax.astra.client.core.query.Filters;
import com.datastax.astra.client.core.query.Projection;
import com.datastax.astra.client.databases.Database;
import java.util.Optional;

public class Example {

  public static void main(String[] args) {
    // Get an existing collection
    DataAPIClient client = DataAPIClients.clientHCD("USERNAME", "PASSWORD");
    Database database = client.getDatabase("API_ENDPOINT", "KEYSPACE_NAME");
    Collection<Document> collection = database.getCollection("COLLECTION_NAME");

    // Find a document
    Filter filter = Filters.eq("metadata.language", "English");
    CollectionFindOneOptions options =
        new CollectionFindOneOptions().projection(Projection.exclude("is_checked_out", "title"));
    Optional<Document> result = collection.findOne(filter, options);
    System.out.println(result);
  }
}

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

Python
TypeScript
Java
curl

from astrapy import DataAPIClient
from astrapy.authentication import UsernamePasswordTokenProvider
from astrapy.constants import Environment
from astrapy.constants import SortMode

# Get an existing collection
client = DataAPIClient(environment=Environment.HCD)
database = client.get_database(
    "API_ENDPOINT",
    token=UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
)
collection = database.get_collection(
    "COLLECTION_NAME", keyspace="KEYSPACE_NAME"
)

# Find a document
result = collection.find_one(
    {
        "$and": [
            {"is_checked_out": False},
            {"number_of_pages": {"$lt": 300}},
        ]
    },
    sort={
        "rating": SortMode.ASCENDING,
        "title": SortMode.DESCENDING,
    },
    projection={"is_checked_out": True, "title": True},
)

print(result)

import {
  DataAPIClient,
  UsernamePasswordTokenProvider,
} from "@datastax/astra-db-ts";

// Get an existing collection
const client = new DataAPIClient({ environment: "hcd" });
const database = client.db("API_ENDPOINT", {
  token: new UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
});
const collection = database.collection("COLLECTION_NAME", {
  keyspace: "KEYSPACE_NAME",
});

// Find a document
(async function () {
  const result = await collection.findOne(
    {
      $and: [{ is_checked_out: false }, { number_of_pages: { $lt: 300 } }],
    },
    {
      sort: {
        rating: 1, // ascending
        title: -1, // descending
      },
      projection: {
        is_checked_out: true,
        title: true,
      },
    },
  );

  console.log(result);
})();

import com.datastax.astra.client.DataAPIClient;
import com.datastax.astra.client.DataAPIClients;
import com.datastax.astra.client.collections.Collection;
import com.datastax.astra.client.collections.commands.options.CollectionFindOneOptions;
import com.datastax.astra.client.collections.definition.documents.Document;
import com.datastax.astra.client.core.query.Filter;
import com.datastax.astra.client.core.query.Filters;
import com.datastax.astra.client.core.query.Projection;
import com.datastax.astra.client.core.query.Sort;
import com.datastax.astra.client.databases.Database;
import java.util.Optional;

public class Example {

  public static void main(String[] args) {
    // Get an existing collection
    DataAPIClient client = DataAPIClients.clientHCD("USERNAME", "PASSWORD");
    Database database = client.getDatabase("API_ENDPOINT", "KEYSPACE_NAME");
    Collection<Document> collection = database.getCollection("COLLECTION_NAME");

    // Find a document
    Filter filter =
        Filters.and(Filters.eq("is_checked_out", false), Filters.lt("number_of_pages", 300));
    CollectionFindOneOptions options =
        new CollectionFindOneOptions()
            .sort(Sort.ascending("rating"), Sort.descending("title"))
            .projection(Projection.include("is_checked_out", "title"));
    Optional<Document> result = collection.findOne(filter, options);
    System.out.println(result);
  }
}

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, or projection clause. Dot notation, which is used to reference nested fields, should not be escaped.

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
  }
}

Python
TypeScript
Java
curl

from astrapy import DataAPIClient
from astrapy.authentication import UsernamePasswordTokenProvider
from astrapy.constants import Environment
from astrapy.constants import SortMode

# Get an existing collection
client = DataAPIClient(environment=Environment.HCD)
database = client.get_database(
    "API_ENDPOINT",
    token=UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
)
collection = database.get_collection(
    "COLLECTION_NAME", keyspace="KEYSPACE_NAME"
)

# Find a document
result = collection.find_one(
    {
        "$and": [
            {"areas.r&&d": False},
            {"costs.price&.usd": {"$lt": 300}},
        ]
    },
    sort={"costs.price&.usd": SortMode.ASCENDING},
    projection={"areas.r&&d": True, "costs.price&.cad": True},
)

print(result)

import {
  DataAPIClient,
  UsernamePasswordTokenProvider,
} from "@datastax/astra-db-ts";

// Get an existing collection
const client = new DataAPIClient({ environment: "hcd" });
const database = client.db("API_ENDPOINT", {
  token: new UsernamePasswordTokenProvider("USERNAME", "PASSWORD"),
});
const collection = database.collection("COLLECTION_NAME", {
  keyspace: "KEYSPACE_NAME",
});

// Find a document
(async function () {
  const result = await collection.findOne(
    {
      $and: [{ "areas.r&&d": false }, { "costs.price&.usd": { $lt: 300 } }],
    },
    {
      sort: {
        "costs.price&.usd": 1, // ascending
      },
      projection: {
        "areas.r&&d": true,
        "costs.price&.cad": true,
      },
    },
  );

  console.log(result);
})();

import com.datastax.astra.client.DataAPIClient;
import com.datastax.astra.client.DataAPIClients;
import com.datastax.astra.client.collections.Collection;
import com.datastax.astra.client.collections.commands.options.CollectionFindOneOptions;
import com.datastax.astra.client.collections.definition.documents.Document;
import com.datastax.astra.client.core.query.Filter;
import com.datastax.astra.client.core.query.Filters;
import com.datastax.astra.client.core.query.Projection;
import com.datastax.astra.client.core.query.Sort;
import com.datastax.astra.client.databases.Database;
import java.util.Optional;

public class Example {

  public static void main(String[] args) {
    // Get an existing collection
    DataAPIClient client = DataAPIClients.clientHCD("USERNAME", "PASSWORD");
    Database database = client.getDatabase("API_ENDPOINT", "KEYSPACE_NAME");
    Collection<Document> collection = database.getCollection("COLLECTION_NAME");

    // Find a document
    Filter filter =
        Filters.and(Filters.eq("areas.r&&d", false), Filters.lt("costs.price&.usd", 300));
    CollectionFindOneOptions options =
        new CollectionFindOneOptions()
            .sort(Sort.ascending("costs.price&.usd"))
            .projection(Projection.include("areas.r&&d", "costs.price&.cad"));
    Optional<Document> result = collection.findOne(filter, options);
    System.out.println(result);
  }
}

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}
  }
}'

Client reference

Python
TypeScript
Java
curl

For more information, see the client reference.

Client reference documentation is not applicable for HTTP.

Find a document

Result

Parameters

Examples

Use a document’s ID to find a document

Use filters to find a document

Use vector search to find a document

Use sorting to find a document

Include only specific fields in the response

Exclude specific fields from the response

Use filter, sort, and projection together

Work with `.` and `&` in field names

Client reference

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