File <| (owner == root or owner == bin) and group == sysadmin |>


Given, tables:   RailsResources, <RailsMap>, RailsParameters

(
(RailsParameters.value = 'root' and 
  RailsParameters.map_id = RailsMap.id and
  RailsMap.key = 'owner' and 
  RailsMap.resource_id = RailsResources.id and
  RailsResources.type = 'File')

 OR 

(RailsParameters.value = 'bin' and 
  RailsParameters.map_id = RailsMap.id and
  RailsMap.key = 'owner' and 
  RailsMap.resource_id = RailsResources.id and
  RailsResources.type = 'File')
)

and

(RailsParameters.value = 'sysadmin' and 
  RailsParameters.map_id = RailsMap.id and
  RailsMap.key = 'group' and 
  RailsMap.resource_id = RailsResources.id and
  RailsResources.type = 'File')
)


------




(
(RailsParameters.value = ? and 
  RailsParameters.map_id = RailsMap.id and
  RailsMap.key = ? and 
  RailsMap.resource_id = RailsResources.id and
  RailsResources.type = 'File')

 OR 

(RailsParameters.value = 'bin' and 
  RailsParameters.map_id = RailsMap.id and
  RailsMap.key = 'owner' and 
  RailsMap.resource_id = RailsResources.id and
  RailsResources.type = 'File')
)

and

(RailsParameters.value = 'sysadmin' and 
  RailsParameters.map_id = RailsMap.id and
  RailsMap.key = 'group' and 
  RailsMap.resource_id = RailsResources.id and
  RailsResources.type = 'File')
)


a = [ 'root', 'owner', .... ]

Resource.find_by_sql([ c, a ])

c = "select Resources.* from Resources, RailsParameters, RailsMap, RailsResources where "
c << ...
a << ...

Resource.find_by_sql([ c, a ])


RailsParameters:
 id => :integer
 map_id => :integer (foreign key into RailsMap)
 value => :string

RailsMap:
 id => :integer
 resource_id => :integer (foreign key into RailsResources)
 key => :string   (e.g., "owner")

RailsResources:
 id => :integer
 type => :string (the "Resource class", e.g., 'File')
 ....  (whatever other stuff you've already got)




class RailsResource < ActiveRecord::Base
  has_many :rails_maps
end

class RailsMap < ActiveRecord::Base
  belongs_to :rails_resource
  has_many :rails_parameters
end




---------------------------

Resource.find(:all, :conditions => [c, a])