title: ActiveRecord customize "AS" identifier
body: <p>some rails code like:</p>
  
  <pre><code>@result = Table_One.join(Table_Two, Table_Three).
  where(id = '1').
  group(:val1, :val2, :amount).
  sum(:amount)
  </code></pre>
  
  <p>will execute sql like:</p>
  
  <pre><code>SELECT SUM(Table_One.amount) as table_one_amount, Table_One.val1 as table_one_val1 ....
  </code></pre>
  
  <p>Just wondering if there is a way to customize the rule of "as", so I can get some sql like</p>
  
  <pre><code>SELECT SUM(Table_One.amount) as t1_a, Table_One.val1 as t1_v1 ....
  </code></pre>