title: SQL: Move column data to other table in same relation
body: <p>I'm wondering if it's possible to move all data from one column in table to another table.
  Here's what i'm trying to do:</p>
  
  <p>Table 1 : users - columns trying to read+move = oauth_access_key and oauth_access_secret</p>
  
  <p>Table 2 : account_users - target columns: oauth_token_key, oauth_token_secret</p>
  
  <p>The relation key between these tables is "user_id".</p>
  
  <p>Is this possible in one query? I know this is easily done in PHP, but i'm wondering if this can be done in plain SQL.</p>
  
  <p>Thanks in advance.</p>