117 lines
4.4 KiB
Ruby
117 lines
4.4 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 '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
|
|
# If true, $explain will be set in QueryMessage that uses this query.
|
|
attr_accessor :explain
|
|
# Either +nil+ or a hash (preferably an OrderedHash).
|
|
attr_accessor :hint
|
|
attr_reader :selector # writer defined below
|
|
|
|
# sel :: A hash describing the query. See the Mongo docs for details.
|
|
#
|
|
# return_fields :: If not +nil+, a single field name or 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.) Default is 0.
|
|
#
|
|
# number_to_return :: Max number of records to return. (Called :limit
|
|
# in calls to Collection#find.) Default is 0 (all
|
|
# records).
|
|
#
|
|
# order_by :: If not +nil+, specifies record sort order. May be a
|
|
# String, Hash, OrderedHash, or Array. If a string, the
|
|
# results will be ordered by that field in ascending
|
|
# order. 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.)
|
|
#
|
|
# hint :: If not +nil+, specifies query hint fields. Must be either
|
|
# +nil+ or a hash (preferably an OrderedHash). See
|
|
# Collection#hint.
|
|
def initialize(sel={}, return_fields=nil, number_to_skip=0, number_to_return=0, order_by=nil, hint=nil)
|
|
@number_to_skip, @number_to_return, @order_by, @hint =
|
|
number_to_skip, number_to_return, order_by, hint
|
|
@explain = nil
|
|
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
|
|
|
|
def fields
|
|
case @fields
|
|
when String
|
|
{@fields => 1}
|
|
when Array
|
|
if @fields.length == 0
|
|
nil
|
|
else
|
|
h = {}
|
|
@fields.each { |field| h[field] = 1 }
|
|
h
|
|
end
|
|
else # nil, anything else
|
|
nil
|
|
end
|
|
end
|
|
|
|
def contains_special_fields
|
|
(@order_by != nil && @order_by.length > 0) || @explain || @hint
|
|
end
|
|
end
|
|
end
|
|
end
|
|
end
|