Scala for Data Science

Casbah query DSL

Using DBObject instances to express queries can be very verbose and somewhat difficult to read. Casbah provides a DSL to express queries much more succinctly. For instance, to get all the documents with the github_id field between 20 and 30, we would write the following:

scala> collection.find("github_id" $gte 20 $lt 30).toList
List[com.mongodb.casbah.Imports.DBObject] = List({ "_id" : { "$oid" : "562e922546f953739c43df0f"} , "github_id" : 23 , "login" : "takeo" , "repos" : ...

The operators provided by the DSL will automatically construct DBObject instances. Using the DSL operators as much as possible generally leads to much more readable and maintainable code.

Going into the full details of the query DSL is beyond the scope of ...