Code Help - Automatically show true or false

stu_c · Aug 15, 2018

Hi all
I am trying to write some IF code on a form to do the following but doesn't seem to work, can someone give me some pointers please

Field Names
DateIn
DateOut
Avaliable (Yes/No)

Basically what I need is when DateIn has a date and DateOut is blank then Avaliable field is FALSE, when both DateIn and DateOut have dates then the Avaliable field is TRUE

I am very new to the coding scene so please don't laugh if its completely wrong ;/

Code:

Private Sub DateIn_AfterUpdate()
If Me.DateIn > Null And Me.DateOut = Null Then
Me.VehicleAvaliable = False
 
End If
 
If Me.DateIn > Null And Me.DateOut > Null Then
Me.VehicleAvaliable = True
 
End If
End Sub

Ranman256 · Aug 15, 2018

Null is not a number, you must use IsNull():

If Not IsNull(Me.DateIn) And IsNull(Me.DateOut) Then

(in queries its: [field] is null )

MajP · Aug 15, 2018

can be done in a single line

Code:

Me.VehicleAvaliable = (isDate(me.datein) and isdate(me.dateOut))

MarkK · Aug 15, 2018

But, looking at this pattern, I expect you'll need something more along the lines of...

Code:

Private Sub DateIn_AfterUpdate()
   SetAvailability Me.DateIn, Me.DateOut
End Sub

Private Sub DateOut_AfterUpdate()
   SetAvailability Me.DateIn, Me.DateOut
End Sub

Private Sub Form_Current()
   SetAvailability Me.DateIn, Me.DateOut
End Sub

Private Sub SetAvailability(DateIn as Variant, DateOut as Variant)
   Me.VehicleAvaliable = IsDate(DateIn.Value) And IsDate(DateOut.Value)
End Sub

hth
Mark

Mark_ · Aug 15, 2018

From what I gather, DateIn is not relevant to your needs. You are only checking if the vehicle is out or not, correct? Would you ever have a dateout without a preceeding datein?

This can make some of what you do much easier as you don't really need a flag, you just need to check if DateOut is null or blank. Then everything that would otherwise be driven by an "Available" flag is based off of DateOut.

Pat Hartman · Aug 16, 2018

What you are trying to do is a violation of second normal form. You are creating a column whose value is dependent on other columns rather than the primary key.

As Mark_ suggested, eliminate the flag and just keep the dates. If IsNull(DateIn) = False then the vehicle is available.

Code Help - Automatically show true or false

stu_c

Registered User.

Ranman256

Well-known member

MajP

You've got your good things, and you've got mine.

MarkK

bit cruncher

Mark_

Longboard on the internet

Pat Hartman

Super Moderator

Similar threads

Users who are viewing this thread