Description of problem:
Sorting different tables by different keys produces ISE


Version-Release number of selected component (if applicable):
Satellite-6.0.3-RHEL-6-20140612.1


How reproducible:
always


Steps to Reproduce:
1. Go to Compute Resources page:
     Infrastructure -> Compute Resources
2. Attempt to sort by "Type" (click on "Type" in table heading)

OR:

1. Go to Subnets page:
     Infrastructure -> Subnets
2. Attempt to sort by "Domain" (click on "Domain" in table heading)


Actual results:
Error appears


Expected results:
Should be sorted by given column


Additional info:
Sorting compute resources by Type:

Processing by ComputeResourcesController#index as HTML
  Parameters: {"order"=>"type ASC"}
Operation FAILED: the field 'type' in the order statement is not valid field for search
  Rendered common/500.html.erb within layouts/application (4.4ms)
  Rendered layouts/base.html.erb (1.1ms)
Completed 500 Internal Server Error in 22ms (Views: 7.1ms | ActiveRecord: 0.0ms)

Sorting subnets by Domain:

Processing by SubnetsController#index as HTML
  Parameters: {"order"=>"domains ASC"}
Operation FAILED: the field 'domains' in the order statement is not valid field for search
  Rendered common/500.html.erb within layouts/application (7.1ms)
  Rendered layouts/base.html.erb (1.5ms)
Completed 500 Internal Server Error in 28ms (Views: 11.1ms | ActiveRecord: 0.0ms)