Question

I have made a form in ms-access to get a query output according to the form.

The sql in the access query being:

SELECT w.* FROM work_log1 AS w, [task name] AS t WHERE t.task_name=forms!
[Accenture QC]!combo4 And t.task_id=w.task_name And w.activity_start_date Between  
forms ![Accenture QC]!text0 And forms![Accenture QC]!text11 
and w.[TAT] = forms![Accenture QC]!combo46

Now everything is working fine, but i want to remove the last filter line if the combo46 is blank.

I have made the sql somehow like this:

and iif(forms![Accenture QC]!combo46 = '', t.task_id=w.task_name ,
t.task_id=w.task_name   and w.[TAT] = forms![Accenture QC]!combo46)

Is this the right way to do this, what if there was only this TAT filter to be applied?

I mean if how to write something like this:

"SELECT w.* FROM work_log1 AS w where (w.[TAT] = forms![Accenture QC]!combo46 
OR forms![Accenture QC]!combo46 Is Null)" 

Thanks

Answer 1

Currently the last part of your WHERE clause is …

and w.[TAT] = forms![Accenture QC]!combo46

If your goal is to ignore that constraint on w.[TAT] when combo46 is Null, try this:

AND (w.[TAT] = forms![Accenture QC]!combo46
    OR forms![Accenture QC]!combo46 Is Null)

This could be less straightforward if “blank” could mean anything other than Null … eg an empty (zero-length) string or space characters. You could capture all those possibilities in one expression.

Len(Trim(forms![Accenture QC]!combo46 & "")) = 0

In the latest version of your question’s query …

SELECT w.*
FROM work_log1 AS w
where
       w.[TAT] = forms![Accenture QC]!combo46 
    OR Len(Trim(forms![Accenture QC]!combo46 & "")) = 0