title: Delphi and Firedac : query Active vs query Open
body: <p>Most of my application's forms use 2 or more db grids : basically, the user clicks a record in main grid and get child results in a secondary grid.</p>
  
  <p>All my primary DBGrids <code>FDQueries</code> (that is the one with SELECT) have been set on the form but none are "active", they fire on <code>FormShow</code>.</p>
  
  <p>I noticed that, wether I write :</p>
  
  <pre><code>FDQuery1.Active := True;
  </code></pre>
  
  <p>or</p>
  
  <pre><code>FDQuery1.Open;
  </code></pre>
  
  <p>the result is the same : my rows are displayed in the main DBGrid.</p>
  
  <p>Accordingly, I call <code>Close</code> or <code>Active := False</code> on <code>FormClose</code>.</p>
  
  <p>But there must be a difference between those approaches and this is the subject of my question : what is the difference between <code>Query.Open</code> and <code>Query.Active := True;</code> ?</p>
  
  <p>What should I use if there is any significant difference ?</p>
  
  <p>Thanks in advance</p>
  
  <p>Math, getting less and less noob as you take the time to answer my questions :)</p>
  
  <p>SIDE NOTE : my INSERT and UPDATE queries are set up with a CLEAR then, SQL.ADD, then Parameters declaration and finally an ExecSQL</p>