Sharepoint list validation syntax question?

Question

I'm trying to get this SharePoint list validation formula to work.

I ultimately want to make sure the date value in my [Date of Appointment] column is greater than the date value in my [Date Followed-Up] column, if [Date Followed-Up] is filled in.

Here's what I tried:

=IF(AND([Date Followed-Up]<>"", [Date of Appointment]>[Date Followed-Up]), [Date of Appointment], "Needs updating")

Any thoughts? Thanks in advance!

Answer 1

The list validation needs simply to return TRUE for the validation to pass.

There is no need for your IF:

=AND([Date Followed-Up]<>"", [Date of Appointment]>[Date Followed-Up])

I'm not sure if comparing your field with "" will work though, I would try with the ISBLANK:

=OR(ISBLANK([Date Followed-Up]),[Date of Appointment]>[Date Followed-Up])

Answer 2

In SharePoint list validation the result of your formula should be true/false.

For your case, try using below formula:

=IF(ISBLANK([Date Followed-Up]), true, [Date of Appointment]>[Date Followed-Up])

This will ensure that if Date Followed-Up is blank then it should allow you to add/edit the list item.

Or simply you can use the formula like below:

=OR(ISBLANK([Date Followed-Up]), [Date of Appointment] > [Date Followed-Up])

Official documentations:

1. IF function.
2. IS functions.
3. OR function.