mongo-ruby-driver/lib/mongo/query.rb

84 lines
3.3 KiB
Ruby

# --
# Copyright (C) 2008-2009 10gen Inc.
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License, version 3, as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License
# for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# ++
require 'socket'
require 'mongo/collection'
require 'mongo/message'
module XGen
module Mongo
module Driver
# A query against a collection. A query's selector is a hash. See the
# Mongo documentation for query details.
class Query
attr_accessor :number_to_skip, :number_to_return, :order_by
attr_reader :selector, :fields # writers defined below
# sel :: A hash describing the query. See the Mongo docs for details.
#
# return_fields :: If not +nil+, an array of field names. Only those
# fields will be returned. (Called :fields in calls
# to Collection#find.)
#
# number_to_skip :: Number of records to skip before returning
# records. (Called :offset in calls to
# Collection#find.)
#
# number_to_return :: Max number of records to return. (Called :limit
# in calls to Collection#find.)
#
# order_by :: If not +nil+, specifies record sort order. May be either
# a hash or an array. If an array, it should be an array
# of field names which will all be sorted in ascending
# order. If a hash, it may be either a regular Hash or an
# OrderedHash. The keys should be field names, and the
# values should be 1 (ascending) or -1 (descending). Note
# that if it is a regular Hash then sorting by more than
# one field probably will not be what you intend because
# key order is not preserved. (order_by is called :sort in
# calls to Collection#find.)
def initialize(sel={}, return_fields=nil, number_to_skip=0, number_to_return=0, order_by=nil)
@number_to_skip, @number_to_return, @order_by = number_to_skip, number_to_return, order_by
self.selector = sel
self.fields = return_fields
end
# Set query selector hash. If sel is a string, it will be used as a
# $where clause. (See Mongo docs for details.)
def selector=(sel)
@selector = case sel
when nil
{}
when String
{"$where" => sel}
when Hash
sel
end
end
# Set fields to return. If +val+ is +nil+ or empty, all fields will be
# returned.
def fields=(val)
@fields = val
@fields = nil if @fields && @fields.empty?
end
end
end
end
end