IsNull
Using the ISNULL Function
In this tutorial you will learn how to use the IsNull Function.
The IsNull function returns a Boolean value indicating whether an expression is NULL or not.
=IsNull( expression )
expression a valid value
In this example we will use the String "Alex".
The result is 0.
If we checked IsNull(Null) we would get -1 in return.
 Query
The results using a Query would be
SELECT IsNull("Alex");
 FORM
In a Form you could set the Default Value of a Textbox to
=IsNull("Alex")
 VBA
In a Form add a TEXTBOX control and rename it "txtIsNull", then you could add the following in the Load Event.
Private Sub Form_Load()
txtIsNull = IsNull("Alex")
End Sub
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By: Alex Hedley
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