Skip to content


Subversion checkout URL

You can clone with
Download ZIP
A Scala DSL for MongoDB
Scala Other
Pull request Compare This branch is 375 commits behind master.
Fetching latest commit...
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.


Rogue is a type-safe internal Scala DSL for constructing and executing find and modify commands against MongoDB in the Lift web framework. It is fully expressive with respect to the basic options provided by MongoDB's native query language, but in a type-safe manner, building on the record types specified in your Lift models. An example:

Venue where (_.mayor eqs 1234) and (_.categories contains "Thai") fetch(10)

The type system enforces the following constraints:

  • the fields must actually belong to the record (e.g., mayor is a field on the Venue record)
  • the field type must match the operand type (e.g., mayor is an IntField)
  • the operator must make sense for the field type (e.g., categories is a MongoListField[String])

In addition, the type system ensures that certain builder methods are only used in certain circumstances. For example, take this more complex query:

Venue where (_.closed eqs false) orderAsc(_.popularity) limit(10) modify (_.closed setTo true) updateMulti

This query purportedly finds the 10 least popular open venues and closes them. However, MongoDB does not (currently) allow you to specify limits on modify queries, so Rogue won't let you either. The above will generate a compiler error.

Constructions like this:

def myMayorships = Venue where (_.mayor eqs 1234) limit(5)

will also not compile, here because a limit is being specified twice. Other similar constraints are in place to prevent you from accidentally doing things you don't want to do anyway.

Building and Installation

Use sbt (simple-build-tool) to build:

$ sbt clean update package

The finished jar will be in target/.

Or if you prefer, packaged JARs are available on Add the following line to your sbt project file to pull them in:

val rogue = "com.foursquare" %% "rogue" % "1.0.15" withSources()

More Examples

QueryTest.scala contains sample Records and examples of every kind of query supported by Rogue. It also indicates what each query translates to in MongoDB's JSON query language. It's a good place to look when getting started using Rogue.

NB: The examples in QueryTest only construct query objects; none are actually executed. Once you have a query object, the following operations are supported (listed here because they are not demonstrated in QueryTest):

For "find" query objects

val query = Venue where (_.venuename eqs "Starbucks")
query.get() // equivalent to query.fetch(1).headOption
query.foreach{v: Venue => ... }
query.fetchBatch(pageSize){vs: List[Venue] => ...}

For "modify" query objects

val modify = query modify (_.popularity inc 1)


The latest release is 1.0.18. See the changelog for more details.

Lots of new features in 1.0.18:

  • findAndModify support
  • $or query support
  • efficient .exists query method (thanks Jorge!)
  • support for BsonRecordField and BsonRecordListField (thanks Marc!)
  • type-safe foreign key condtions, e.g., Tip.where(_.venueid eqs venueObj) (thanks dtaylor!)

Please see QueryTest.scala for examples of these new features.

Other recent notable changes:

  • .toString produces runnable javascript commands for mongodb console
  • added tests for constructions that should not compile
  • selectCase() builder method for select()ing via case class
  • added blockingBulkDelete_!! method which takes a WriteConcern
  • index hinting support
  • support for selecting subfields
  • support for $maxScan and $comment addSpecial parameters on find() queries
  • explain() method on BaseQuery (thanks tjulien!)
  • query signatures: string version of a query with all values blanked out
  • support for indicating when a query clause is intended to hit an index (for runtime index checking, if you wish to implement it)


liftweb (2.2, 2.3), mongodb, joda-time, junit. These dependencies are managed by the build system.


Rogue was initially developed by Foursquare Labs for internal use -- nearly all of the MongoDB queries in foursquare's code base go through this library. The current maintainers are:

Contributions welcome!

Something went wrong with that request. Please try again.