Combo Box, "ALL" value

[Remillard]

Noob user with a noob question.
Briefly, my table tracks Staff and a lot of information about them, one of which is which "Site", whose value can be 1 of 3 choices, I'll call them "Site1", "Site2", and "Site3".
I have a form used to pass values to a query, to find records based on which Site the staff works at and on another field; we'll call it "InsuranceExpiryDate".
I have a Combo Box on the form, called "Site" which I have populated myself with, "Site1", "Site2", "Site3" and I want to have an option for "ALL" so the query can find everyone in a particular Site whose insurance is expired or just everyone in the db whose insurance is expired.


I'm building this db for users who are not Access literate at all so I only want them to be able to choose a site or "all" from the drop down, and a date from a date field calendar.
So, long story short, how does one do "ALL" in a combo box?

Cheers!

[pbaldy]

How about

http://access.mvps.org/access/forms/frm0043.htm

along with

http://access.mvps.org/access/queries/qry0001.htm

[Remillard]

Thanks for the links. I ran into Union queries in my searching for an answer but was hoping for just adding something to a value list. In the first link it looks like the second option fits my needs better but there is a cautionary in the info:

---------
"One requires the use of an Union query, and the other one requires a callback function to fill the control. Generally using an Union query is easier. Callback functions are important in certain cases, but perhaps an overkill in this situation."
---------

Not sure what a Callback function is or why it's overkill. This is the function. I'm just unclear where the code goes.

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If the RowSourceType is set to "Value List", you can simply concatenate "(All)" as the first choice when the form opens. So if the RowSource of the control Combo0 is

"Hello"; "World"

Then this code will change it to

"(All)";"Hello"; "World"

'******* Code Start ********
Private Sub Form_Open(Cancel As Integer)
With Me.Combo0
.RowSourceType = "Value List"
.RowSource = "(All);" & .RowSource
End With
End Sub
'******* Code End ********

[pbaldy]

Based on the first line of the code, it goes in the open event of the form. Personally I virtually always use a table rather than a value list. Seems more dynamic and maintainable to me.