[Rails] help with temporary database tables

I'm running Ruby 1.9.2 and Rails 3.0.7. I'm having problems inserting
data into a temporary database table.

I can create a temporary table with the code:
<code>
class TempHelper
def self.create_temp
begin
ActiveRecord::Schema.define do
create_table (:temps), :temporary => true do |t|
t.string :name
t.string :value
end
end
return true
rescue Exception => err
return err.message
end
end
end
</code>

But I can not insert any data into it:
<code>
irb(main):001:0> TempHelper.create_temp
-- create_table(:temps, {:temporary=>true})
-> 0.0440s
=> true
irb(main):002:0> Temp.count
=> 0
irb(main):003:0> t = Temp.new(:name => 'name', :value => 'value')
=> #<Temp id: nil, name: "name", value: "value">
irb(main):004:0> t.save
NoMethodError: undefined method `name' for nil:NilClass
from /usr/local/ruby-1.9.2/lib/ruby/gems/1.9.1/gems/
activesupport-3.0.7/lib/active_support/whiny_nil.rb:48:in
`method_missing'
...
irb(main):005:0> t.class
=> Temp(Table doesn't exist)
</code>

I can provide the complete traceback if it will help.

I do not understand why this is not working. For this testing, I'm
using sqlite3. Is that the problem?

Thanx in advance.