title: sql: scan row(s) with unknown number of columns (select * from ...)
body: <p>I have a table <code>t</code> containing a lot of columns, and my sql is like this: <code>select * from t</code>. Now I only want to scan one column or two from the wide returned row set. However, the sql.Scan accepts <code>dest ...interface{}</code> as arguments. Does it mean I have to scan everything and use only the column I needed?</p>
  
  <p>I know I could change the sql from <code>select *</code> to <code>select my_favorite_rows</code>, however, in this case, I have no way to change the sql.</p>