MongoDB\Collection::createIndex()

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Definition
Return Values
Errors/Exceptions
Examples
See Also

Definition

MongoDB\Collection::createIndex

Create an index for the collection.

function createIndex(array|object $key, array $options = []): string

This method has the following parameters:

Parameter Type Description

$key

array|object

Specifies the field or fields to index and the index order.

For example, the following specifies a descending index on the username field:

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[ 'username' => -1 ]

$options array Optional. An array specifying the desired options.

The $options parameter accepts all index options that your MongoDB version supports. MongoDB includes the following options:

Option	Type	Description
`commitQuorum`	string\|integer	Optional. Specifies how many data-bearing members of a replica set, including the primary, must complete the index builds successfully before the primary marks the indexes as ready. This option accepts the same values for the `w` field in a write concern plus `"votingMembers"`, which indicates all voting data-bearing nodes. This is not supported for server versions prior to 4.4 and will result in an exception at execution time if used. New in version 1.7.
`comment`	mixed	Optional. Enables users to specify an arbitrary comment to help trace the operation through the database profiler, currentOp output, and logs. This is not supported for server versions prior to 4.4 and will result in an exception at execution time if used. New in version 1.13.
`unique`	boolean	Optional. Creates a unique index.
`collation`	array\|object	Optional. Specifies the collation for the index. 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.
`partialFilterExpression`	array\|object	Optional. Creates a partial index.
`sparse`	boolean	Optional. Creates a sparse index.
`expireAfterSeconds`	integer	Optional. Creates a TTL index.
`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. New in version 1.3.
`name`	string	Optional. A name that uniquely identifies the index. By default, MongoDB creates index names based on the key.
`background`	string	Optional. Instructs MongoDB to build the index as a background process.
`2dsphereIndexVersion`	integer	Optional. Overrides the server’s default version for a 2dsphere index.
`session`	MongoDB\Driver\Session	Optional. Client session to associate with the operation. New in version 1.3.
`writeConcern`	MongoDB\Driver\WriteConcern	Optional. Write concern to use for the operation. Defaults to the collection’s write concern. It is not possible to specify a write concern for individual operations as part of a transaction. Instead, set the `writeConcern` option when starting the transaction with startTransaction.

For a full list of the supported index creation options, refer to the createIndexes command reference in the MongoDB manual.

Return Values

The name of the created index as a string.

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).

Examples

Create a Compound Index

The following example creates a compound index on the borough and cuisine fields in the restaurants collection in the test database.

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<?php

$collection = (new MongoDB\Client)->selectCollection('test', 'restaurants');

$indexName = $collection->createIndex(['borough' => 1, 'cuisine' => 1]);

var_dump($indexName);

The output would then resemble:

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string(19) "borough_1_cuisine_1"

Create a Partial Index

The following example adds a partial index on the borough field in the restaurants collection in the test database. The partial index indexes only documents where the borough field exists.

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<?php

$collection = (new MongoDB\Client)->selectCollection('test', 'restaurants');

$indexName = $collection->createIndex(
   ['borough' => 1],
   [
       'partialFilterExpression' => [
           'borough' => ['$exists' => true],
       ],
   ]
);

var_dump($indexName);

The output would then resemble:

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string(9) "borough_1"

MongoDB\Collection::createIndex()

Definition

Return Values

Errors/Exceptions

Examples

Create a Compound Index

Create a Partial Index

See Also