Datatype problemer

with Query do
begin
  SQL.Clear;
  SQL.Add('Update StaffLeftCompany');
  SQL.Add('Set DateOfITUpdate = :DateOfITUpdate,');
  SQL.Add(' reminder = reminder + 1 ');
  SQL.Add('Where SecurityCode = :SecurityCode');
  Parameters.ParamByName('DateOfITUpdate').Value := DateOf(now);
  Parameters.ParamByName('SecurityCode').Value := ADOQuery1.FieldByName('SECURITYCODE').AsString;
  Prepared := true;
  ExecSQL;
end;
finally
  Query.Free;
end;

"The data type ntext and ntext are incompatible in the equal to operator"

Min SECURITYCODE har datatype: ntext

den havde før nvarchar(max) og der havde jeg så fejlen:

"The data type nvarchar(max) and ntext are incompatible in the equal to operator"