It is possible to put an unbound check box on a form, set its Triple State
property to Yes, and then design the query so that it matches the Yes record
if the check box is checked, the No records if it is unchecked, or all
records if it is Null.
In the end, though, this is going to be a considerable amount of work for a
quite poor outcome. The triple state check box is a confusing interface,
since there's no visible difference beween No and Null under recent
versions of Windows. Even worse, the query critieria is long, confusing to
enter, difficult to maintain, inefficient to execute, and may even be
unstable.
It depends on your data, but it may be a much better solution would be to
use a normalized design rather than many check boxes in the one table. For
an example, see:
Don't use Yes/No fields to store preferences
at:
http://allenbrowne.com/casu-23.html
If you really want to do it anyway, you will end up with the WHERE clause of
your query (in SQL View) looking like this:
WHERE (IIf([Forms].[Form1].[Chk1]=True, [MyYesNo1]=True,
IIf([Forms].[Form1].[Chk1]=False, [MyYesNo1]=False, True)))
AND (IIf([Forms].[Form1].[Chk2]=True, [MyYesNo2]=True,
IIf([Forms].[Form1].[Chk2]=False, [MyYesNo2]=False, True)))
AND ...