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• MongoDB\Collection::findOne()

MongoDB\Collection::findOne()

Definition

MongoDB\Collection::findOne

Finds a single document matching the query.

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

This method has the following parameters:

Parameter	Type	Description
$filter	array|object	Optional. The filter criteria that specifies the documents to query.
$options	array	Optional. An array specifying the desired options.

The $options parameter supports the following options:

Option	Type	Description
projection	array|object	Optional. 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.
sort	array|object	Optional. The sort specification for the ordering of the results.
skip	integer	Optional. Number of documents to skip. Defaults to 0.
allowDiskUse	boolean	Optional. Enables writing to temporary files. When set to true, queries can write data to the _tmp sub-directory in the dbPath directory.
collation	array|object	Optional. 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. This option is available in MongoDB 3.4+ and will result in an exception at execution time if specified for an older server version. 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	string	Optional. A comment to attach to the query to help interpret and trace query profile data.
hint	string|array|object	Optional. 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.
maxTimeMS	integer	Optional. The cumulative time limit in milliseconds for processing operations on the cursor. MongoDB aborts the operation at the earliest following interrupt point.
readConcern	MongoDB\Driver\ReadConcern	Optional. Read concern to use for the operation. Defaults to the collection’s read concern. This is not supported for server versions prior to 3.2 and will result in an exception at execution time if used. 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 with startTransaction.
readPreference	MongoDB\Driver\ReadPreference	Optional. Read preference to use for the operation. Defaults to the collection’s read preference.
session	MongoDB\Driver\Session	Optional. Client session to associate with the operation. Sessions are not supported for server versions prior to 3.6. New in version 1.3.
typeMap	array	Optional. 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.
max	array|object	Optional. The exclusive upper bound for a specific index. New in version 1.2.
maxScan	integer	Optional. Maximum number of documents or index keys to scan when executing the query. Deprecated since version 1.4. New in version 1.2.
min	array|object	Optional. The inclusive lower bound for a specific index. New in version 1.2.
returnKey	boolean	Optional. If true, returns only the index keys in the resulting documents. New in version 1.2.
showRecordId	boolean	Optional. 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.
modifiers	array|object	Optional. Meta operators that modify the output or behavior of a query. Use of these operators is deprecated in favor of named options.

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 driver 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 driver (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.

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$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.

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$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"
  }
}

See Also

• MongoDB\Collection::find()
• find command reference in the MongoDB manual

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