RMongo (version 0.0.25)

dbGetQueryForKeys-methods: Performing a MongoDB query and only return back certain keys

Description

Send a json query to mongodb. The output is a data.frame object and will work properly only if the mongoDB collection contains primitive data types. It may not work properly if there are any embedded documents or arrays.

Usage

dbGetQueryForKeys(rmongo.object, collection, query, keys, skip=0, limit=1000)

Arguments

rmongo.object

The RMongo object.

collection

The name of the collection the query is being performed upon.

query

A JSON string query. See http://www.mongodb.org/display/DOCS/Advanced+Queries for more information on the MongoDB query language.

keys

A JSON string query. See http://www.mongodb.org/display/DOCS/Advanced+Queries for more information on the MongoDB query language.

skip

Offset the resultset. Can be used with limit to perform pagination.

limit

Limits the resultset size.

See Also

mongoDbConnect

Examples

  mongo <- mongoDbConnect("test")
  output <- dbInsertDocument(mongo, "test_data", '{"foo": "bar"}')  
  output <- dbGetQueryForKeys(mongo, 'test_data', '{"foo": "bar"}', '{"foo":1}')
  print(output)