Abfrage verhält sich in Access anders als über ADO in Delphi

[hirnstroem]

Delphi-Quellcode:

  with ADODataSet_UserDepartment do
  begin
    Close;
    if DepartmentID <> '' then
    begin
      CommandText := 'SELECT * FROM [User] WHERE Username LIKE :Username AND Forename LIKE :Forename AND Surname LIKE :Surname AND DepartmentID = :DepartmentID ORDER BY Username;';
      Parameters.ParamByName('DepartmentID').Value :=  DepartmentID;
    end
    else CommandText := 'SELECT * FROM [User] WHERE Username LIKE :Username AND Forename LIKE :Forename AND Surname LIKE :Surname ORDER BY Username;';
    Parameters.ParamByName('Username').Value :=
      PrepareSearchString(Username) + '%';
    Parameters.ParamByName('Forename').Value :=
      PrepareSearchString(Forename) + '%';
    Parameters.ParamByName('Surname').Value :=
      PrepareSearchString(Surname) + '%';
    Open;
  end;

Access ist Krieg.

Ich benutze jetzt einfach zwei verschiedene Abfragen.