Parent

Mongo::Collection

A named collection of documents in a database.

Attributes

acceptable_latency[RW]

Read Preference

db[R]
hint[R]
name[R]
pk_factory[R]
read[RW]

Read Preference

tag_sets[RW]

Read Preference

write_concern[R]

Public Class Methods

new(name, db, opts={}) click to toggle source

Initialize a collection object.

@param [String, Symbol] name the name of the collection. @param [DB] db a MongoDB database instance.

@option opts [String, Integer, Symbol] :w (1) Set default number of nodes to which a write

should be acknowledged

@option opts [Boolean] :j (false) Set journal acknowledgement @option opts [Integer] :wtimeout (nil) Set replica set acknowledgement timeout @option opts [Boolean] :fsync (false) Set fsync acknowledgement.

Notes about write concern:
  These write concern options will be used for insert, update, and remove methods called on this  
  Collection instance. If no value is provided, the default values set on this instance's DB will be used. 
  These option values can be overridden for any invocation of insert, update, or remove.

@option opts [:create_pk] :pk (BSON::ObjectId) A primary key factory to use

other than the default BSON::ObjectId.

@option opts [:primary, :secondary] :read The default read preference for queries

initiates from this connection object. If +:secondary+ is chosen, reads will be sent
to one of the closest available secondary nodes. If a secondary node cannot be located, the
read will be sent to the primary. If this option is left unspecified, the value of the read
preference for this collection's associated Mongo::DB object will be used.

@raise [InvalidNSName]

if collection name is empty, contains '$', or starts or ends with '.'

@raise [TypeError]

if collection name is not a string or symbol

@return [Collection]

@core collections constructor_details

# File lib/mongo/collection.rb, line 68
def initialize(name, db, opts={})
  if db.is_a?(String) && name.is_a?(Mongo::DB)
    warn "Warning: the order of parameters to initialize a collection have changed. " +
         "Please specify the collection name first, followed by the db. This will be made permanent" +
         "in v2.0."
    db, name = name, db
  end

  case name
  when Symbol, String
  else
    raise TypeError, "new_name must be a string or symbol"
  end

  name = name.to_s

  if name.empty? or name.include? ".."
    raise Mongo::InvalidNSName, "collection names cannot be empty"
  end
  if name.include? "$"
    raise Mongo::InvalidNSName, "collection names must not contain '$'" unless name =~ /((^\$cmd)|(oplog\.\$main))/
  end
  if name.match(/^\./) or name.match(/\.$/)
    raise Mongo::InvalidNSName, "collection names must not start or end with '.'"
  end

  if opts.respond_to?(:create_pk) || !opts.is_a?(Hash)
    warn "The method for specifying a primary key factory on a Collection has changed.\n" +
      "Please specify it as an option (e.g., :pk => PkFactory)."
    pk_factory = opts
  else
    pk_factory = nil
  end

  @db, @name  = db, name
  @connection = @db.connection
  @logger     = @connection.logger
  @cache_time = @db.cache_time
  @cache      = Hash.new(0)
  unless pk_factory
    @write_concern = get_write_concern(opts, db)
    @read =  opts[:read] || @db.read
    Mongo::ReadPreference::validate(@read)
    @tag_sets           = opts.fetch(:tag_sets, @db.tag_sets)
    @acceptable_latency = opts.fetch(:acceptable_latency, @db.acceptable_latency)
  end
  @pk_factory = pk_factory || opts[:pk] || BSON::ObjectId
  @hint = nil
end

Public Instance Methods

<<(doc_or_docs, opts={}) click to toggle source
Alias for: insert
[](name) click to toggle source

Return a sub-collection of this collection by name. If 'users' is a collection, then 'users.comments' is a sub-collection of users.

@param [String, Symbol] name

the collection to return

@raise [Mongo::InvalidNSName]

if passed an invalid collection name

@return [Collection]

the specified sub-collection
# File lib/mongo/collection.rb, line 139
def [](name)
  name = "#{self.name}.#{name}"
  return Collection.new(name, db) if !db.strict? ||
    db.collection_names.include?(name.to_s)
  raise "Collection #{name} doesn't exist. Currently in strict mode."
end
aggregate(pipeline=nil, opts={}) click to toggle source

Perform an aggregation using the aggregation framework on the current collection. @note Aggregate requires server version >= 2.1.1 @note Field References: Within an expression, field names must be quoted and prefixed by a dollar sign ($).

@example Define the pipeline as an array of operator hashes:

coll.aggregate([ {"$project" => {"last_name" => 1, "first_name" => 1 }}, {"$match" => {"last_name" => "Jones"}} ])

@param [Array] pipeline Should be a single array of pipeline operator hashes.

'$project' Reshapes a document stream by including fields, excluding fields, inserting computed fields, 
renaming fields,or creating/populating fields that hold sub-documents.

'$match' Query-like interface for filtering documents out of the aggregation pipeline.

'$limit' Restricts the number of documents that pass through the pipeline.

'$skip' Skips over the specified number of documents and passes the rest along the pipeline.

'$unwind' Peels off elements of an array individually, returning one document for each member.

'$group' Groups documents for calculating aggregate values.

'$sort' Sorts all input documents and returns them to the pipeline in sorted order.

@option opts [:primary, :secondary] :read Read preference indicating which server to perform this query

on. See Collection#find for more details.

@option opts [String] :comment (nil) a comment to include in profiling logs

@return [Array] An Array with the aggregate command's results.

@raise MongoArgumentError if operators either aren't supplied or aren't in the correct format. @raise MongoOperationFailure if the aggregate command fails.

# File lib/mongo/collection.rb, line 659
def aggregate(pipeline=nil, opts={})
  raise MongoArgumentError, "pipeline must be an array of operators" unless pipeline.class == Array
  raise MongoArgumentError, "pipeline operators must be hashes" unless pipeline.all? { |op| op.class == Hash }

  hash = BSON::OrderedHash.new
  hash['aggregate'] = self.name
  hash['pipeline'] = pipeline

  result = @db.command(hash, command_options(opts))
  unless Mongo::Support.ok?(result)
    raise Mongo::OperationFailure, "aggregate failed: #{result['errmsg']}"
  end

  return result["result"]
end
capped?() click to toggle source

Indicate whether this is a capped collection.

@raise [Mongo::OperationFailure]

if the collection doesn't exist.

@return [Boolean]

# File lib/mongo/collection.rb, line 124
def capped?
  [1, true].include? @db.command({:collstats => @name})['capped']
end
count(opts={}) click to toggle source

Get the number of documents in this collection.

@option opts [Hash] :query ({}) A query selector for filtering the documents counted. @option opts [Integer] :skip (nil) The number of documents to skip. @option opts [Integer] :limit (nil) The number of documents to limit. @option opts [:primary, :secondary] :read Read preference for this command. See Collection#find for

more details.

@option opts [String] :comment (nil) a comment to include in profiling logs

@return [Integer]

# File lib/mongo/collection.rb, line 962
def count(opts={})
  find(opts[:query],
       :skip  => opts[:skip],
       :limit => opts[:limit],
       :read  => opts[:read],
       :comment => opts[:comment]).count(true)
end
Also aliased as: size
create_index(spec, opts={}) click to toggle source

Create a new index.

@param [String, Array] spec

should be either a single field name or an array of
[field name, direction] pairs. Directions should be specified
as Mongo::ASCENDING, Mongo::DESCENDING, or Mongo::GEO2D.

Note that geospatial indexing only works with versions of MongoDB >= 1.3.3+. Keep in mind, too,
that in order to geo-index a given field, that field must reference either an array or a sub-object
where the first two values represent x- and y-coordinates. Examples can be seen below.

Also note that it is permissible to create compound indexes that include a geospatial index as
long as the geospatial index comes first.

If your code calls create_index frequently, you can use Collection#ensure_index to cache these calls
and thereby prevent excessive round trips to the database.

@option opts [Boolean] :unique (false) if true, this index will enforce a uniqueness constraint. @option opts [Boolean] :background (false) indicate that the index should be built in the background. This

feature is only available in MongoDB >= 1.3.2.

@option opts [Boolean] :drop_dups (nil) If creating a unique index on a collection with pre-existing records,

this option will keep the first document the database indexes and drop all subsequent with duplicate values.

@option opts [Integer] :min (nil) specify the minimum longitude and latitude for a geo index. @option opts [Integer] :max (nil) specify the maximum longitude and latitude for a geo index.

@example Creating a compound index using a hash: (Ruby 1.9 and above)

@posts.create_index({'subject' => Mongo::ASCENDING, 'created_at' => Mongo::DESCENDING})

@example Creating a compound index:

@posts.create_index([['subject', Mongo::ASCENDING], ['created_at', Mongo::DESCENDING]])

@example Creating a geospatial index:

@restaurants.create_index([['location', Mongo::GEO2D]])

# Note that this will work only if 'location' represents x,y coordinates:
{'location': [0, 50]}
{'location': {'x' => 0, 'y' => 50}}
{'location': {'latitude' => 0, 'longitude' => 50}}

@example A geospatial index with alternate longitude and latitude:

@restaurants.create_index([['location', Mongo::GEO2D]], :min => 500, :max => 500)

@return [String] the name of the index created.

@core indexes create_index-instance_method

# File lib/mongo/collection.rb, line 533
def create_index(spec, opts={})
  opts[:dropDups] = opts[:drop_dups] if opts[:drop_dups]
  field_spec      = parse_index_spec(spec)
  opts            = opts.dup
  name            = opts.delete(:name) || generate_index_name(field_spec)
  name            = name.to_s if name
  generate_indexes(field_spec, name, opts)
  name
end
distinct(key, query=nil, opts={}) click to toggle source

Return a list of distinct values for key across all documents in the collection. The key may use dot notation to reach into an embedded object.

@param [String, Symbol, OrderedHash] key or hash to group by. @param [Hash] query a selector for limiting the result set over which to group. @param [Hash] opts the options for this distinct operation.

@option opts [:primary, :secondary] :read Read preference indicating which server to perform this query

on. See Collection#find for more details.

@option opts [String] :comment (nil) a comment to include in profiling logs

@example Saving zip codes and ages and returning distinct results.

@collection.save({:zip => 10010, :name => {:age => 27}})
@collection.save({:zip => 94108, :name => {:age => 24}})
@collection.save({:zip => 10010, :name => {:age => 27}})
@collection.save({:zip => 99701, :name => {:age => 24}})
@collection.save({:zip => 94108, :name => {:age => 27}})

@collection.distinct(:zip)
  [10010, 94108, 99701]
@collection.distinct("name.age")
  [27, 24]

# You may also pass a document selector as the second parameter
# to limit the documents over which distinct is run:
@collection.distinct("name.age", {"name.age" => {"$gt" => 24}})
  [27]

@return [Array] an array of distinct values.

# File lib/mongo/collection.rb, line 885
def distinct(key, query=nil, opts={})
  raise MongoArgumentError unless [String, Symbol].include?(key.class)
  command            = BSON::OrderedHash.new
  command[:distinct] = @name
  command[:key]      = key.to_s
  command[:query]    = query

  @db.command(command, command_options(opts))["values"]
end
drop() click to toggle source

Drop the entire collection. USE WITH CAUTION.

# File lib/mongo/collection.rb, line 599
def drop
  @db.drop_collection(@name)
end
drop_index(name) click to toggle source

Drop a specified index.

@param [String] name

@core indexes

# File lib/mongo/collection.rb, line 580
def drop_index(name)
  if name.is_a?(Array)
    return drop_index(index_name(name))
  end
  @cache[name.to_s] = nil
  @db.drop_index(@name, name)
end
drop_indexes() click to toggle source

Drop all indexes.

@core indexes

# File lib/mongo/collection.rb, line 591
def drop_indexes
  @cache = {}

  # Note: calling drop_indexes with no args will drop them all.
  @db.drop_index(@name, '*')
end
ensure_index(spec, opts={}) click to toggle source

Calls create_index and sets a flag to not do so again for another X minutes. this time can be specified as an option when initializing a Mongo::DB object as options Any changes to an index will be propagated through regardless of cache time (e.g., a change of index direction)

The parameters and options for this methods are the same as those for Collection#create_index.

@example Call sequence:

Time t: @posts.ensure_index([['subject', Mongo::ASCENDING])  -- calls create_index and
  sets the 5 minute cache
Time t+2min : @posts.ensure_index([['subject', Mongo::ASCENDING])  -- doesn't do anything
Time t+3min : @posts.ensure_index([['something_else', Mongo::ASCENDING])  -- calls create_index
  and sets 5 minute cache
Time t+10min : @posts.ensure_index([['subject', Mongo::ASCENDING])  -- calls create_index and
  resets the 5 minute counter

@return [String] the name of the index.

# File lib/mongo/collection.rb, line 559
def ensure_index(spec, opts={})
  now             = Time.now.utc.to_i
  opts[:dropDups] = opts[:drop_dups] if opts[:drop_dups]
  field_spec      = parse_index_spec(spec)
  name            = opts[:name] || generate_index_name(field_spec)
  name            = name.to_s if name

  if !@cache[name] || @cache[name] <= now
    generate_indexes(field_spec, name, opts)
  end

  # Reset the cache here in case there are any errors inserting. Best to be safe.
  @cache[name] = now + @cache_time
  name
end
find(selector={}, opts={}) click to toggle source

Query the database.

The selector argument is a prototype document that all results must match. For example:

collection.find({"hello" => "world"})

only matches documents that have a key "hello" with value "world". Matches can have other keys *in addition* to "hello".

If given an optional block find will yield a Cursor to that block, close the cursor, and then return nil. This guarantees that partially evaluated cursors will be closed. If given no block find returns a cursor.

@param [Hash] selector

a document specifying elements which must be present for a
document to be included in the result set. Note that in rare cases,
(e.g., with $near queries), the order of keys will matter. To preserve
key order on a selector, use an instance of BSON::OrderedHash (only applies
to Ruby 1.8).

@option opts [Array, Hash] :fields field names that should be returned in the result

set ("_id" will be included unless explicitly excluded). By limiting results to a certain subset of fields,
you can cut down on network traffic and decoding time. If using a Hash, keys should be field
names and values should be either 1 or 0, depending on whether you want to include or exclude
the given field.

@option opts [:primary, :secondary] :read The default read preference for queries

initiates from this connection object. If +:secondary+ is chosen, reads will be sent
to one of the closest available secondary nodes. If a secondary node cannot be located, the
read will be sent to the primary. If this option is left unspecified, the value of the read
preference for this Collection object will be used.

@option opts [Integer] :skip number of documents to skip from the beginning of the result set @option opts [Integer] :limit maximum number of documents to return @option opts [Array] :sort an array of [key, direction] pairs to sort by. Direction should

be specified as Mongo::ASCENDING (or :ascending / :asc) or Mongo::DESCENDING (or :descending / :desc)

@option opts [String, Array, OrderedHash] :hint hint for query optimizer, usually not necessary if

using MongoDB > 1.1

@option opts [Boolean] :snapshot (false) if true, snapshot mode will be used for this query.

Snapshot mode assures no duplicates are returned, or objects missed, which were preset at both the start and
end of the query's execution.
For details see http://www.mongodb.org/display/DOCS/How+to+do+Snapshotting+in+the+Mongo+Database

@option opts [Boolean] :batch_size (100) the number of documents to returned by the database per

GETMORE operation. A value of 0 will let the database server decide how many results to return.
This option can be ignored for most use cases.

@option opts [Boolean] :timeout (true) when true, the returned cursor will be subject to

the normal cursor timeout behavior of the mongod process. When +false+, the returned cursor will
never timeout. Note that disabling timeout will only work when #find is invoked with a block.
This is to prevent any inadvertent failure to close the cursor, as the cursor is explicitly
closed when block code finishes.

@option opts [Integer] :max_scan (nil) Limit the number of items to scan on both collection scans and indexed queries.. @option opts [Boolean] :show_disk_loc (false) Return the disk location of each query result (for debugging). @option opts [Boolean] :return_key (false) Return the index key used to obtain the result (for debugging). @option opts [Block] :transformer (nil) a block for transforming returned documents.

This is normally used by object mappers to convert each returned document to an instance of a class.

@option opts [String] :comment (nil) a comment to include in profiling logs

@raise [ArgumentError]

if timeout is set to false and find is not invoked in a block

@raise [RuntimeError]

if given unknown options

@core find find-instance_method

# File lib/mongo/collection.rb, line 221
def find(selector={}, opts={})
  opts               = opts.dup
  fields             = opts.delete(:fields)
  fields             = ["_id"] if fields && fields.empty?
  skip               = opts.delete(:skip) || skip || 0
  limit              = opts.delete(:limit) || 0
  sort               = opts.delete(:sort)
  hint               = opts.delete(:hint)
  snapshot           = opts.delete(:snapshot)
  batch_size         = opts.delete(:batch_size)
  timeout            = (opts.delete(:timeout) == false) ? false : true
  max_scan           = opts.delete(:max_scan)
  return_key         = opts.delete(:return_key)
  transformer        = opts.delete(:transformer)
  show_disk_loc      = opts.delete(:show_disk_loc)
  comment            = opts.delete(:comment)
  read               = opts.delete(:read) || @read
  tag_sets           = opts.delete(:tag_sets) || @tag_sets
  acceptable_latency = opts.delete(:acceptable_latency) || @acceptable_latency

  if timeout == false && !block_given?
    raise ArgumentError, "Collection#find must be invoked with a block when timeout is disabled."
  end

  if hint
    hint = normalize_hint_fields(hint)
  else
    hint = @hint        # assumed to be normalized already
  end

  raise RuntimeError, "Unknown options [#{opts.inspect}]" unless opts.empty?

  cursor = Cursor.new(self, {
    :selector           => selector,
    :fields             => fields,
    :skip               => skip,
    :limit              => limit,
    :order              => sort,
    :hint               => hint,
    :snapshot           => snapshot,
    :timeout            => timeout,
    :batch_size         => batch_size,
    :transformer        => transformer,
    :max_scan           => max_scan,
    :show_disk_loc      => show_disk_loc,
    :return_key         => return_key,
    :read               => read,
    :tag_sets           => tag_sets,
    :comment            => comment,
    :acceptable_latency => acceptable_latency
  })

  if block_given?
    begin
      yield cursor
    ensure
      cursor.close
    end
    nil
  else
    cursor
  end
end
find_and_modify(opts={}) click to toggle source

Atomically update and return a document using MongoDB's findAndModify command. (MongoDB > 1.3.0)

@option opts [Hash] :query ({}) a query selector document for matching the desired document. @option opts [Hash] :update (nil) the update operation to perform on the matched document. @option opts [Array, String, OrderedHash] :sort ({}) specify a sort option for the query using any

of the sort options available for Cursor#sort. Sort order is important if the query will be matching
multiple documents since only the first matching document will be updated and returned.

@option opts [Boolean] :remove (false) If true, removes the the returned document from the collection. @option opts [Boolean] :new (false) If true, returns the updated document; otherwise, returns the document

prior to update.

@return [Hash] the matched document.

@core findandmodify find_and_modify-instance_method

# File lib/mongo/collection.rb, line 617
def find_and_modify(opts={})
  cmd = BSON::OrderedHash.new
  cmd[:findandmodify] = @name
  cmd.merge!(opts)
  cmd[:sort] = Mongo::Support.format_order_clause(opts[:sort]) if opts[:sort]

  @db.command(cmd)['value']
end
find_one(spec_or_object_id=nil, opts={}) click to toggle source

Return a single object from the database.

@return [OrderedHash, Nil]

a single document or nil if no result is found.

@param [Hash, ObjectId, Nil] spec_or_object_id a hash specifying elements

which must be present for a document to be included in the result set or an
instance of ObjectId to be used as the value for an _id query.
If nil, an empty selector, {}, will be used.

@option opts [Hash]

any valid options that can be send to Collection#find

@raise [TypeError]

if the argument is of an improper type.
# File lib/mongo/collection.rb, line 300
def find_one(spec_or_object_id=nil, opts={})
  spec = case spec_or_object_id
         when nil
           {}
         when BSON::ObjectId
           {:_id => spec_or_object_id}
         when Hash
           spec_or_object_id
         else
           raise TypeError, "spec_or_object_id must be an instance of ObjectId or Hash, or nil"
         end
  find(spec, opts.merge(:limit => -1)).next_document
end
group(opts, condition={}, initial={}, reduce=nil, finalize=nil) click to toggle source

Perform a group aggregation.

@param [Hash] opts the options for this group operation. The minimum required are :initial

and :reduce.

@option opts [Array, String, Symbol] :key (nil) Either the name of a field or a list of fields to group by (optional). @option opts [String, BSON::Code] :keyf (nil) A JavaScript function to be used to generate the grouping keys (optional). @option opts [String, BSON::Code] :cond ({}) A document specifying a query for filtering the documents over

which the aggregation is run (optional).

@option opts [Hash] :initial the initial value of the aggregation counter object (required). @option opts [String, BSON::Code] :reduce (nil) a JavaScript aggregation function (required). @option opts [String, BSON::Code] :finalize (nil) a JavaScript function that receives and modifies

each of the resultant grouped objects. Available only when group is run with command
set to true.

@option opts [:primary, :secondary] :read Read preference indicating which server to perform this group

on. See Collection#find for more details.

@option opts [String] :comment (nil) a comment to include in profiling logs

@return [Array] the command response consisting of grouped items.

# File lib/mongo/collection.rb, line 762
def group(opts, condition={}, initial={}, reduce=nil, finalize=nil)
  if opts.is_a?(Hash)
    return new_group(opts)
  else
    warn "Collection#group no longer take a list of parameters. This usage is deprecated and will be remove in v2.0." +
         "Check out the new API at http://api.mongodb.org/ruby/current/Mongo/Collection.html#group-instance_method"
  end

  reduce = BSON::Code.new(reduce) unless reduce.is_a?(BSON::Code)

  group_command = {
    "group" => {
      "ns"      => @name,
      "$reduce" => reduce,
      "cond"    => condition,
      "initial" => initial
    }
  }

  if opts.is_a?(Symbol)
    raise MongoArgumentError, "Group takes either an array of fields to group by or a JavaScript function" +
      "in the form of a String or BSON::Code."
  end

  unless opts.nil?
    if opts.is_a? Array
      key_type = "key"
      key_value = {}
      opts.each { |k| key_value[k] = 1 }
    else
      key_type  = "$keyf"
      key_value = opts.is_a?(BSON::Code) ? opts : BSON::Code.new(opts)
    end

    group_command["group"][key_type] = key_value
  end

  finalize = BSON::Code.new(finalize) if finalize.is_a?(String)
  if finalize.is_a?(BSON::Code)
    group_command['group']['finalize'] = finalize
  end

  result = @db.command(group_command)

  if Mongo::Support.ok?(result)
    result["retval"]
  else
    raise OperationFailure, "group command failed: #{result['errmsg']}"
  end
end
hint=(hint=nil) click to toggle source

Set a hint field for query optimizer. Hint may be a single field name, array of field names, or a hash (preferably an [OrderedHash]). If using MongoDB > 1.1, you probably don't ever need to set a hint.

@param [String, Array, OrderedHash] hint a single field, an array of

fields, or a hash specifying fields
# File lib/mongo/collection.rb, line 152
def hint=(hint=nil)
  @hint = normalize_hint_fields(hint)
  self
end
index_information() click to toggle source

Get information on the indexes for this collection.

@return [Hash] a hash where the keys are index names.

@core indexes

# File lib/mongo/collection.rb, line 933
def index_information
  @db.index_information(@name)
end
insert(doc_or_docs, opts={}) click to toggle source

Insert one or more documents into the collection.

@param [Hash, Array] doc_or_docs

a document (as a hash) or array of documents to be inserted.

@return [ObjectId, Array]

The _id of the inserted document or a list of _ids of all inserted documents.

@return [[ObjectId, Array], [Hash, Array]]

1st, the _id of the inserted document or a list of _ids of all inserted documents.
2nd, a list of invalid documents.
Return this result format only when :collect_on_error is true.

@option opts [String, Integer, Symbol] :w (1) Set default number of nodes to which a write

should be acknowledged

@option opts [Boolean] :j (false) Set journal acknowledgement @option opts [Integer] :wtimeout (nil) Set replica set acknowledgement timeout @option opts [Boolean] :fsync (false) Set fsync acknowledgement.

Notes on write concern:
  Options provided here will override any write concern options set on this collection,
  its database object, or the current connection. See the options for +DB#get_last_error+.

@option opts [Boolean] :continue_on_error (false) If true, then

continue a bulk insert even if one of the documents inserted
triggers a database assertion (as in a duplicate insert, for instance).
If not acknowledging writes, the list of ids returned will
include the object ids of all documents attempted on insert, even
if some are rejected on error. When acknowledging writes, any error will raise an 
OperationFailure exception.
MongoDB v2.0+.

@option opts [Boolean] :collect_on_error (false) if true, then

collects invalid documents as an array. Note that this option changes the result format.

@raise [Mongo::OperationFailure] will be raised iff :w > 0 and the operation fails.

@core insert insert-instance_method

# File lib/mongo/collection.rb, line 379
def insert(doc_or_docs, opts={})
  doc_or_docs = [doc_or_docs] unless doc_or_docs.is_a?(Array)
  doc_or_docs.collect! { |doc| @pk_factory.create_pk(doc) }
  write_concern = get_write_concern(opts, self)
  result = insert_documents(doc_or_docs, @name, true, write_concern, opts)
  result.size > 1 ? result : result.first
end
Also aliased as: <<
map_reduce(map, reduce, opts={}) click to toggle source

Perform a map-reduce operation on the current collection.

@param [String, BSON::Code] map a map function, written in JavaScript. @param [String, BSON::Code] reduce a reduce function, written in JavaScript.

@option opts [Hash] :query ({}) a query selector document, like what's passed to find, to limit

the operation to a subset of the collection.

@option opts [Array] :sort ([]) an array of [key, direction] pairs to sort by. Direction should

be specified as Mongo::ASCENDING (or :ascending / :asc) or Mongo::DESCENDING (or :descending / :desc)

@option opts [Integer] :limit (nil) if passing a query, number of objects to return from the collection. @option opts [String, BSON::Code] :finalize (nil) a javascript function to apply to the result set after the

map/reduce operation has finished.

@option opts [String] :out (nil) a valid output type. In versions of MongoDB prior to v1.7.6,

this option takes the name of a collection for the output results. In versions 1.7.6 and later,
this option specifies the output type. See the core docs for available output types.

@option opts [Boolean] :keeptemp (false) if true, the generated collection will be persisted. The default

is false. Note that this option has no effect is versions of MongoDB > v1.7.6.

@option opts [Boolean ] :verbose (false) if true, provides statistics on job execution time. @option opts [Boolean] :raw (false) if true, return the raw result object from the map_reduce command, and not

the instantiated collection that's returned by default. Note if a collection name isn't returned in the
map-reduce output (as, for example, when using :out => { :inline => 1 }), then you must specify this option
or an ArgumentError will be raised.

@option opts [:primary, :secondary] :read Read preference indicating which server to run this map-reduce

on. See Collection#find for more details.

@option opts [String] :comment (nil) a comment to include in profiling logs

@return [Collection, Hash] a Mongo::Collection object or a Hash with the map-reduce command's results.

@raise ArgumentError if you specify { :out => { :inline => true }} but don't specify :raw => true.

@see www.mongodb.org/display/DOCS/MapReduce Offical MongoDB map/reduce documentation.

@core mapreduce map_reduce-instance_method

# File lib/mongo/collection.rb, line 708
def map_reduce(map, reduce, opts={})
  map    = BSON::Code.new(map) unless map.is_a?(BSON::Code)
  reduce = BSON::Code.new(reduce) unless reduce.is_a?(BSON::Code)
  raw    = opts.delete(:raw)

  hash = BSON::OrderedHash.new
  hash['mapreduce'] = self.name
  hash['map'] = map
  hash['reduce'] = reduce
  hash.merge! opts
  if hash[:sort]
    hash[:sort] = Mongo::Support.format_order_clause(hash[:sort])
  end

  result = @db.command(hash, command_options(opts))
  unless Mongo::Support.ok?(result)
    raise Mongo::OperationFailure, "map-reduce failed: #{result['errmsg']}"
  end

  if raw
    result
  elsif result["result"]
    if result['result'].is_a? BSON::OrderedHash and result['result'].has_key? 'db' and result['result'].has_key? 'collection'
      otherdb = @db.connection[result['result']['db']]
      otherdb[result['result']['collection']]
    else
      @db[result["result"]]
    end
  else
    raise ArgumentError, "Could not instantiate collection from result. If you specified " +
      "{:out => {:inline => true}}, then you must also specify :raw => true to get the results."
  end
end
Also aliased as: mapreduce
mapreduce(map, reduce, opts={}) click to toggle source
Alias for: map_reduce
options() click to toggle source

Return a hash containing options that apply to this collection. For all possible keys and values, see DB#create_collection.

@return [Hash] options that apply to this collection.

# File lib/mongo/collection.rb, line 941
def options
  @db.collections_info(@name).next_document['options']
end
remove(selector={}, opts={}) click to toggle source

Remove all documents from this collection.

@param [Hash] selector

If specified, only matching documents will be removed.

@option opts [String, Integer, Symbol] :w (1) Set default number of nodes to which a write

should be acknowledged

@option opts [Boolean] :j (false) Set journal acknowledgement @option opts [Integer] :wtimeout (nil) Set replica set acknowledgement timeout @option opts [Boolean] :fsync (false) Set fsync acknowledgement.

Notes on write concern:
  Options provided here will override any write concern options set on this collection,
  its database object, or the current connection. See the options for +DB#get_last_error+.

@example remove all documents from the 'users' collection:

users.remove
users.remove({})

@example remove only documents that have expired:

users.remove({:expire => {"$lte" => Time.now}})

@return [Hash, true] Returns a Hash containing the last error object if acknowledging writes

Otherwise, returns true.

@raise [Mongo::OperationFailure] will be raised iff :w > 0 and the operation fails.

@core remove remove-instance_method

# File lib/mongo/collection.rb, line 416
def remove(selector={}, opts={})
  write_concern = get_write_concern(opts, self)
  message = BSON::ByteBuffer.new("\00\\00\\00\\00"")
  BSON::BSON_RUBY.serialize_cstr(message, "#{@db.name}.#{@name}")
  message.put_int(0)
  message.put_binary(BSON::BSON_CODER.serialize(selector, false, true, @connection.max_bson_size).to_s)

  instrument(:remove, :database => @db.name, :collection => @name, :selector => selector) do
    if Mongo::WriteConcern.gle?(write_concern)
      @connection.send_message_with_gle(Mongo::Constants::OP_DELETE, message, @db.name, nil, write_concern)
    else
      @connection.send_message(Mongo::Constants::OP_DELETE, message)
      true
    end
  end
end
rename(new_name) click to toggle source

Rename this collection.

Note: If operating in auth mode, the client must be authorized as an admin to perform this operation.

@param [String] new_name the new name for this collection

@return [String] the name of the new collection.

@raise [Mongo::InvalidNSName] if new_name is an invalid collection name.

# File lib/mongo/collection.rb, line 905
def rename(new_name)
  case new_name
  when Symbol, String
  else
    raise TypeError, "new_name must be a string or symbol"
  end

  new_name = new_name.to_s

  if new_name.empty? or new_name.include? ".."
    raise Mongo::InvalidNSName, "collection names cannot be empty"
  end
  if new_name.include? "$"
    raise Mongo::InvalidNSName, "collection names must not contain '$'"
  end
  if new_name.match(/^\./) or new_name.match(/\.$/)
    raise Mongo::InvalidNSName, "collection names must not start or end with '.'"
  end

  @db.rename_collection(@name, new_name)
  @name = new_name
end
save(doc, opts={}) click to toggle source

Save a document to this collection.

@param [Hash] doc

the document to be saved. If the document already has an '_id' key,
then an update (upsert) operation will be performed, and any existing
document with that _id is overwritten. Otherwise an insert operation is performed.

@return [ObjectId] the _id of the saved document.

@option opts [Hash] :w, :j, :wtimeout, :fsync Set the write concern for this operation.

:w > 0 will run a +getlasterror+ command on the database to report any assertion. 
:j will confirm a write has been committed to the journal,
:wtimeout specifies how long to wait for write confirmation,
:fsync will confirm that a write has been fsynced. 
Options provided here will override any write concern options set on this collection,
its database object, or the current connection. See the options
for DB#get_last_error.

@raise [Mongo::OperationFailure] will be raised iff :w > 0 and the operation fails.

# File lib/mongo/collection.rb, line 333
def save(doc, opts={})
  if doc.has_key?(:_id) || doc.has_key?('_id')
    id = doc[:_id] || doc['_id']
    update({:_id => id}, doc, opts.merge!({:upsert => true}))
    id
  else
    insert(doc, opts)
  end
end
size(opts={}) click to toggle source
Alias for: count
stats() click to toggle source

Return stats on the collection. Uses MongoDB's collstats command.

@return [Hash]

# File lib/mongo/collection.rb, line 948
def stats
  @db.command({:collstats => @name})
end
update(selector, document, opts={}) click to toggle source

Update one or more documents in this collection.

@param [Hash] selector

a hash specifying elements which must be present for a document to be updated. Note:
the update command currently updates only the first document matching the
given selector. If you want all matching documents to be updated, be sure
to specify :multi => true.

@param [Hash] document

a hash specifying the fields to be changed in the selected document,
or (in the case of an upsert) the document to be inserted

@option opts [Boolean] :upsert (false) if true, performs an upsert (update or insert) @option opts [Boolean] :multi (false) update all documents matching the selector, as opposed to

just the first matching document. Note: only works in MongoDB 1.1.3 or later.

@option opts [String, Integer, Symbol] :w (1) Set default number of nodes to which a write

should be acknowledged

@option opts [Boolean] :j (false) Set journal acknowledgement @option opts [Integer] :wtimeout (nil) Set replica set acknowledgement timeout @option opts [Boolean] :fsync (false) Set fsync acknowledgement.

Notes on write concern:
  Options provided here will override any write concern options set on this collection,
  its database object, or the current connection. See the options for DB#get_last_error.

@return [Hash, true] Returns a Hash containing the last error object if acknowledging writes.

Otherwise, returns true.

@raise [Mongo::OperationFailure] will be raised iff :w > 0 and the operation fails.

@core update update-instance_method

# File lib/mongo/collection.rb, line 463
def update(selector, document, opts={})
  # Initial byte is 0.
  write_concern = get_write_concern(opts, self)
  message = BSON::ByteBuffer.new("\00\\00\\00\\00"")
  BSON::BSON_RUBY.serialize_cstr(message, "#{@db.name}.#{@name}")
  update_options  = 0
  update_options += 1 if opts[:upsert]
  update_options += 2 if opts[:multi]

  # Determine if update document has modifiers and check keys if so
  check_keys = document.keys.first.to_s.start_with?("$") ? false : true

  message.put_int(update_options)
  message.put_binary(BSON::BSON_CODER.serialize(selector, false, true).to_s)
  message.put_binary(BSON::BSON_CODER.serialize(document, check_keys, true, @connection.max_bson_size).to_s)

  instrument(:update, :database => @db.name, :collection => @name, :selector => selector, :document => document) do
    if Mongo::WriteConcern.gle?(write_concern)
      @connection.send_message_with_gle(Mongo::Constants::OP_UPDATE, message, @db.name, nil, write_concern)
    else
      @connection.send_message(Mongo::Constants::OP_UPDATE, message)
    end
  end
end

Protected Instance Methods

command_options(opts) click to toggle source

Parse common options for read-only commands from an input @opts hash and return a hash suitable for passing to DB#command.

# File lib/mongo/collection.rb, line 976
def command_options(opts)
  out = {}

  if read = opts[:read]
    Mongo::ReadPreference::validate(read)
  else
    read = @read
  end
  out[:read] = read
  out[:comment] = opts[:comment] if opts[:comment]
  out
end
normalize_hint_fields(hint) click to toggle source
# File lib/mongo/collection.rb, line 989
def normalize_hint_fields(hint)
  case hint
  when String
    {hint => 1}
  when Hash
    hint
  when nil
    nil
  else
    h = BSON::OrderedHash.new
    hint.to_a.each { |k| h[k] = 1 }
    h
  end
end

[Validate]

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