Tib_Query have property isEmpty which show is the dataset is empty
but which tib_query must be prepare first , otherwise this property
always return true.
instead of use recordcount <> 0, the SysRecordCount function will
prepare the query if not already prepared. and issue 'Select Count
(*)' SQL.

Why need prepare the ib_query before test isempty property. because
in our problem , those query will not be prepared until is need.
in this case , recordcount will be better.

Any suggestion.