title: Delphi - FieldByName.AsString - good practice
body: <p>I've read an blog post(at this moment I can't find the link) where the author was saying that is faster to assign a local variable than using ADOQuery.FieldByName('...').asString or TSQLQuery.FieldByName('...').asString, when parsing an entire query with several thousands of records. I don't see the difference between </p>
  
  <pre><code>var aLocalField: TField;
  ....
  aLocalField := ADOQuery.FieldByName('...');
  ..
  ShowMessage(aLocalField.asString)
  </code></pre>
  
  <p>and by using directly </p>
  
  <pre><code>ShowMessage(ADOQuery.FieldByName('...').asString);
  </code></pre>
  
  <p>Blog post did not say anything about the database type or Delphi version. Is this solution related to one or another(and I'm not talking about obscure/custom database systems)?</p>