createIndex()

MongoDB Driver Function Reference

Creates an index on the collection.
More information can be found in the corresponding entry of the MongoDB Manual.

<collection>.createIndex([<name>, ]<keys>[, <options>[, <commitQuorum>]])

Arguments

<collection>		The target collection.
<name>		Index name
<keys>		A BSON document specifying the index keys.
<options>		A BOSN document specifying options.
<commitQuorum>		A string or integer specifying the commit quorum.

Options

{ unique: <boolean>, name: <string>, sparse: <boolean>, expireAfterSeconds: <long>, storageEngine: <document> }

unique		Creates a unique index.
name		Provides an index name.
sparse		Index will only reference documents with the specified key.
expireAfterSeconds		Index expiration time.
storageEngine		Storage engine definition.

Example

db.employees.createIndex("salary_ix", { salary: 1 });

Creates an index for the salary key on the employees collection.