Problema con ado, necesito ayuda urgente

[[Caral]]

Hola

Código Delphi [-]
AdoConnection1.BeginTrans;
try
with Query1 do
  Begin
   SQL.Clear;
   SQL.Add('Delete From Estudiante');
   Sql.Add('Where Grado = "09"');
   ExecSQL;
  End;
AdoConnection1.CommitTrans;
except
     on E:Exception do AdoConnection1.RollbackTrans;
end;

Saludos