How to set a numeric field and date field as Null

I suggest you use vbNullString instead of double quotes"".
eg. set a text field to null use
Test = vbNullstring

To set a numeric or date field to null use the keyword Null.
Test=Null

when I use
Test = null

I get an error:  Invalid use of null.

Using:
test = null
Will only work when the tablefield it's connected to allows a zero length.
Just check the fielddefinition in the table.
To have the field just empty you can use the
test = ""

Looks strange, but Null means "not there" and "" means "empty" and they are different for a database !

Nic;o)

Is test a field or variable? How/where are you setting Test to null?

Greetings Nico:

I'm using this in a function and when I use NULL to assign to a numeric field it is giving me an error

either Vbnullstring is also giving me an error


    If IsNull(BegDate) Then
        WorkDays = NULL
        Exit Function
        End If
   

if WorkDays is a variable, it should be declared as a variant data type to accept a null value.

Make for a numeric field sure that the "Required" property is set to "No" to allow Null values in the table.

Nic;o)

Ihave written a function to calculate workdays and a append Query to insert the workdays in to a field.

Here is my total function


Public Function WorkDays(BegDate As Variant, EndDate As Variant) As Integer

    If IsNull(BegDate) Then
        WorkDays = Null
        Exit Function
        End If
    If IsNull(EndDate) Then
        WorkDays = Null
        Exit Function
        End If
    If BegDate > EndDate Then
        WorkDays = Null
        Exit Function
        End If
    If BegDate < #1/1/1980# Then
        WorkDays = Null
        Exit Function
        End If
    If BegDate = EndDate Then
        WorkDays = 0
        Exit Function
        End If

      Dim DateCnt As Variant
      DateCnt = BegDate
     
      Do While DateCnt < EndDate
         If Format(DateCnt, "ddd") <> "Sun" And Format(DateCnt, "ddd") <> "Sat" And _
            IsNull(DLookup("HoliDate", "Holidays", "[HoliDate]=#" & DateCnt & "#")) Then
         WorkDays = WorkDays + 1
         End If
         DateCnt = DateCnt + 1
      Loop
     
      If Format(EndDate, "ddd") = "Sun" Or Format(EndDate, "ddd") = "Sat" Or _
        Not IsNull(DLookup("HoliDate", "Holidays", "[HoliDate]=#" & EndDate & "#")) Then
        WorkDays = WorkDays - 1
        End If
       
   End Function

And this is my append Query

UPDATE TestNull SET TestNull.Field2 = WorkDays(BegDate, EndDate)
;

NICO-
The "Required" property is set to "No"
Error remains

Thanks Ppaldus
I changed it
But  it is giving me an compile error in query expression

Yep, thought you were referring to a form field, but for a function that's indeed the way to get a Null value returned.
But just why activate a function when the data isn't OK ?
And why have both Null and 0 workdays ?

Nic;o)

Make sure field2 has the required set to No

Nic;o)

I only set 0 where Begdate = Enddate

The data is Ok some times there won't be enddate
Then I need Null in workdays.

Later I have to process for the field2 like Where Field2 = Null

I ve already set Field2 required = NO

Looks to me you have the Workdays initially with a null value.
Just ignoring a Null begin and enddate in the queries WHERE clause will have the same effect as setting the Null workdays again to Null.

Nic;o)

I could not find out the exact problem some times it is giveing me error and some times it is working

Bit odd to see an answer follwed by "But  it is giving me an compile error in query expression"

Would have been better when you requested a moderator to delete/refund the question.

Nic;o)

I don't this option Nico
if I don't get asatisfactory answer can i ask the moderator to delete my question?
If so How to ask to delete a question

Thank you for the suggestion

Here's all there is to know:

https://www.experts-exchange.com/help.jsp#hs5

Nic;o)

Thank You