Using @variables:= in delphi query does not work

Question

I have the following problem.

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;

When I run this code I get an exception Incorrect token followed by ":" in ZQuery1.
How do I fix this? I need to use Delphi, because I cannot put this select in a MySQL procedure.
Zeos 6 does not support MySQL procedures that return a resultset.

P.S.
I'm using Delphi 2007 and MySQL 5.1 with ZEOS 6.6.6.
Although I'm pretty sure the versions don't matter.
I'm not willing to switch versions as I'm too far into the project.

Answer 1

This can't be done, you can only parameterize the value. Best you can do is SQL.Text := StringReplace() but you lose the speed of preparing queries.