Too vague. Need more information. Screen shots?

I choose the greenhouse and based on that the query puts the correct nursery tables in the table combo box.  Every greenhouse has different nursery table numbers as you can see in the query result of greenhouse 2 and greenhouse 3. The problem now is that when I put  greenhouse 2 in the first record it is shown correctly but if in the next record I choose greenhouse 3 the table combobox will still show the records for greenhouse 2 which seems ti indicate the query is not updated.

Default Value

In the query I have the default for StageID set to 2 as that is the value for the nursery tables.  In other queries I set to default to 3 for the growth tables. The problem is that the query only runs once. Do you mean that in the Table combo form I set the default value to NTableGrowthformQ and the query will run every time? I'll try that.

Doesn't work

I meant Table combobox default value

I use this string to set the default values for the next record: Me.FromTableCombo.DefaultValue = """" & Me.FromTableCombo.Value & """". When I go to the next record I can leave it or change it.  I got this string from the internet. I don't quite understand it yet but it works.

So, you're trying to set a field value based on a selection in a Combo Box? Correct?
I would use a If Then in the After Update event for the Combo Box.

For example:

If ComboBoxName = YourValue Then
   YourField = SomeValue
elseIf ComboBoxName = YourOtherValue Then
   YourField = SomeOtherValue
end if

Not possible.  It needs to run the query to get the correct answer.  I have over 250 tables in my greenhouses, most of them growth tables (Stage 3), less nursery tables (stage 2) and 2 seeding tables Stage 1) per greenhouse.  To get the combobox to display the right choice of tables it needs to run the query every time I select it.

As you can see in the picture, the nursery tables have 900 holes. When the plants get bigger they are moved to the growth tables that have only 240 holes. Seeding, nursery and growth stage each take 15 days so there is a lot of moving

Usually all the plants from one lot are in the nursery tables in one greenhouse and there is no problem.  However, sometimes one lot is divided over several greenhouses and that is when the choice of tables has to change with the choice of greenhouse.

Do you requery the combo boxes in your code?  You have several combo boxes in your form GrowthF, so you have to make sure they are requeried accordingly.  If they are inter-related, you have to requery them every time the user enters a new value in ANY one of the combo boxes.  For instance, if combo box A affects B, B affects C, and C affects D, then if the user changes A, then B, C, and D all have to be requeried, not just B.

I use comboboxes to limit the input choices for my staff and limit mistakes.  I have now added a refresh button in the form footer which they have to use when they change greenhouse.  This is not ideal but it works.

A affects B and C affects D. A will change rarely, C more often.

In the greenhouse's AfterUpdate event (or Change event), you can requery the necessary combo box(es).  This is done automatically whenever the user changes the greenhouse.  That's better than having the user manually refresh the form.  Also, refreshing the whole form is slower than refreshing just one or two combo boxes in one row.

Hi Kevin,
That doesn't seem to work.  I have put an Afterupdate macro  event in to requery. When I now fill in the form, as soon as I choose a value in the greenhouse combobox the value disappears.

Requery only changes the values inside a combo box; it does not change the value of the control itself, even if it is an invalid choice for the combo box.  See my picture below for an example.  I select "Asia" as the continent, and the country combo box requeries and shows a list of Asian countries.  I select "India" as the country.  Then I select "Africa" as the continent.  The country combo box requeries again and shows a list of African country.  But it still shows "India" as its country value.  It does not disappear.  It would only disappear if something else made it do so.

If the value itself disappears, then the problem lies elsewhere.  Something else is affecting the combo box's value, and it could be any number of things.  I would suggest you do a VBA debug.  Set a break point in the VBA editor, such as in the form's Open event.  When the form opens, it will go right to debug mode.  Press F8 to see the code executes line by line until the combo box value disappears.

How do I access the VBA code for a macro? All I did was create a requery macro in the AfterUpdate property so I don't know how that could have a bug.

Do you have any VBA code at all in your form? Macro certainly could have bugs if not written properly.  But as I said, the problem likely lies elsewhere of the requery action, because requery doesn't blank out data; something else probably does.  Since you don't get any run-time errors (bugs don't always generate errors), the only way is to see your VBA code run line by line.  Also, you could try using Requery in VBA (remove the macro first).  To me, this looks like a simple mystery whose answer couldn't be hidden in plain sight.

The answer *could* be hidden in plain sight.