title: Using @variables:= in delphi query does not work
body: <p>I have the following problem.</p>
  
  <pre><code>ZQuery1.SQL.Text:= 
    ' SELECT                                                  '+
    '   IF(q.rank2 = 1, @rank:= 1, @rank:= @rank + 1) AS rank '+
    '   ,q.* FROM (                                            '+
    '   SELECT groep.id - MinGroepId(groep.id) AS rank2       '+
    '     ,groep.otherfields                                  '+
    '   FROM groep                                            '+
    '   ORDER BY rank2 ) q;                                   ';
  ZQuery.Open;
  </code></pre>
  
  <p>When I run this code I get an exception <code>Incorrect token followed by ":"</code> in ZQuery1.<br>
  How do I fix this? I need to use Delphi, because I cannot put this select in a MySQL procedure.<br>
  Zeos 6 does not support MySQL procedures that return a resultset.</p>
  
  <p>P.S.<br>
  I'm using Delphi 2007 and MySQL 5.1 with ZEOS 6.6.6.<br>
  Although I'm pretty sure the versions don't matter.<br>
  I'm not willing to switch versions as I'm too far into the project.</p>