How to write this date comparison IF statement where it should exclude "Missing" labelled dates?

[mwallman]

Hello,

I have a dates table like this:

ID	Date1	Date2
1	21/05/2018	30/06/2019
2	15/01/2018	31/12/2018
3	24/04/2018	Missing
4	10/02/2018	01/01/2018
5	17/04/2018	Missing

How can I write an IF statement where it is something like IF(Date1<=Date,ID)

But also to add a clause where it excludes dates from Date2 field where they are classified as "Missing"?

[sunny_talwar]

May be this

If(Date1 <= Date2 and Date2 <> 'Missing', ID)

Or if Missing means null, then this

If(Date1 <= Date2 and Len(Trim(Date2)) > 0, ID)