MongoDB\Collection::findOne()

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Definition

Parameters
Return Values
Errors/Exceptions
Behavior
Examples
See Also

Definition

MongoDB\Collection::findOne()

Finds a single document matching the query.

function findOne(
    array|object $filter = [],
    array $options = []
): array|object|null

Parameters

$filter : array|object

The filter criteria that specifies the documents to query.

$options : array

An array specifying the desired options.

Name	Type	Description
allowDiskUse	boolean	Enables writing to temporary files. When set to `true`, queries can write data to the `_tmp` sub-directory in the `dbPath` directory.
allowPartialResults	boolean	For queries against a sharded collection, returns partial results from the `mongos` if some shards are unavailable instead of throwing an error.
codec	MongoDB\Codec\DocumentCodec	The codec to use for encoding or decoding documents. This option is mutually exclusive with the `typeMap` option. Defaults to the collection's codec. Inheritance for a default `codec` option takes precedence over that of the `typeMap` option. New in version 1.17.
collation	array\|object	Collation allows users to specify language-specific rules for string comparison, such as rules for lettercase and accent marks. When specifying collation, the `locale` field is mandatory; all other collation fields are optional. For descriptions of the fields, see Collation Document. If the collation is unspecified but the collection has a default collation, the operation uses the collation specified for the collection. If no collation is specified for the collection or for the operation, MongoDB uses the simple binary comparison used in prior versions for string comparisons.
comment	mixed	Enables users to specify an arbitrary comment to help trace the operation through the database profiler, currentOp output, and logs. The comment can be any valid BSON type since MongoDB 4.4. Earlier server versions only support string values.
hint	string\|array\|object	The index to use. Specify either the index name as a string or the index key pattern as a document. If specified, then the query system will only consider plans using the hinted index. New in version 1.2.
let	array\|object	Map of parameter names and values. Values must be constant or closed expressions that do not reference document fields. Parameters can then be accessed as variables in an aggregate expression context (e.g. `$$var`). This is not supported for server versions prior to 5.0 and will result in an exception at execution time if used. New in version 1.13.
max	array\|object	The exclusive upper bound for a specific index. New in version 1.2.
maxTimeMS	integer	The cumulative time limit in milliseconds for processing operations on the cursor. MongoDB aborts the operation at the earliest following interrupt point.
min	array\|object	The inclusive lower bound for a specific index. New in version 1.2.
projection	array\|object	The projection specification to determine which fields to include in the returned documents. See Project Fields to Return from Query and Projection Operators in the MongoDB manual.
readConcern	MongoDB\Driver\ReadConcern	Read concern to use for the operation. Defaults to the collection's read concern. It is not possible to specify a read concern for individual operations as part of a transaction. Instead, set the `readConcern` option when starting the transaction.
readPreference	MongoDB\Driver\ReadPreference	Read preference to use for the operation. Defaults to the collection's read preference.
returnKey	boolean	If true, returns only the index keys in the resulting documents. New in version 1.2.
session	MongoDB\Driver\Session	Client session to associate with the operation. New in version 1.3.
showRecordId	boolean	Determines whether to return the record identifier for each document. If true, adds a field `$recordId` to the returned documents. New in version 1.2.
skip	integer	Number of documents to skip. Defaults to `0`.
sort	array\|object	The sort specification for the ordering of the results.
typeMap	array	The type map to apply to cursors, which determines how BSON documents are converted to PHP values. Defaults to the collection's type map. This will be used for the returned result document.

Return Values

An array or object for the first document that matched the query, or null if no document matched the query. The return type will depend on the typeMap option.

Errors/Exceptions

MongoDB\Exception\UnsupportedException if options are used and not supported by the selected server (e.g. collation, readConcern, writeConcern).

MongoDB\Exception\InvalidArgumentException for errors related to the parsing of parameters or options.

MongoDB\Driver\Exception\RuntimeException for other errors at the extension level (e.g. connection errors).

Behavior

When evaluating query criteria, MongoDB compares types and values according to its own comparison rules for BSON types, which differs from PHP's comparison and type juggling rules. When matching a special BSON type the query criteria should use the respective BSON class in the extension (e.g. use MongoDB\BSON\ObjectId to match an ObjectId).

Examples

Matching BSON Types in Query Criteria

In the following example, documents in the restaurants collection use an ObjectId for their identifier (the default) and documents in the zips collection use a string. Since ObjectId is a special BSON type, the query criteria for selecting a restaurant must use the MongoDB\BSON\ObjectId class.

<?php
$database = (new MongoDB\Client)->test;
$zip = $database->zips->findOne(['_id' => '10036']);
$restaurant = $database->restaurants->findOne([
    '_id' => new MongoDB\BSON\ObjectId('594d5ef280a846852a4b3f70'),
]);

Projecting Fields

The following example finds a restaurant based on the cuisine and borough fields and uses a projection to limit the fields that are returned.

<?php
$collection = (new MongoDB\Client)->test->restaurants;
$restaurant = $collection->findOne(
    [
        'cuisine' => 'Italian',
        'borough' => 'Manhattan',
    ],
    [
        'projection' => [
            'name' => 1,
            'borough' => 1,
            'cuisine' => 1,
        ],
    ]
);
var_dump($restaurant);

The output would then resemble:

object(MongoDB\Model\BSONDocument)#10 (1) {
  ["storage":"ArrayObject":private]=>
  array(4) {
    ["_id"]=>
    object(MongoDB\BSON\ObjectId)#8 (1) {
      ["oid"]=>
      string(24) "576023c6b02fa9281da3f983"
    }
    ["borough"]=>
    string(9) "Manhattan"
    ["cuisine"]=>
    string(7) "Italian"
    ["name"]=>
    string(23) "Isle Of Capri Resturant"
  }
}