Cross object formula field on child object

Question

Why is this formula on the child object not working? I've created a number field formula on the child (Days_from_Project_Creation__c) and a roll up number field (Opportunity__r.Latest_Create_Date_of_PL__c) on the parent. Both fields are populated correctly. Below is the formula field on the child object that is not working.

IF(Opportunity__r.Latest_Create_Date_of_PL__c = Days_from_Project_Creation__c, TRUE, FALSE)

Answer 1

Try rounding the formula/roll-up summary fields before comparing them. Even though the decimal places are set to the same value, they aren't rounded to that value until after all the calculations are completed--so even though they may look the same when you display them in a page layout, they aren't the same in the calculation. So:

ROUND(Opportunity__r.Latest_Create_Date_of_PL__c) = ROUND(Days_from_Project_Creation__c)

(Also note that you don't need an IF function to return True or False here -- the comparison returns this implicitly.)

Answer 2

This might be it:

I have had this issue before -- the internal value on the child object may actually be, for example, 9.999999999999998 instead of 10, the value displayed. You can see this by doing soql on the field. The number of decimal places is used for rounding, not absolute precision when calculations are done. The RSF will roll up the exact decimal number on the child, not its rounded value.

Answer 3

This looks odd. But please check if number of digits after decimal point is same for both fields. Also try to put both fields in page layout and manually compare both values to ensure that, both are setting correctly.

Answer 4

Try: IF(Opportunity__r.Latest_Create_Date_of_PL__c - Days_from_Project_Creation__c == 0, TRUE, FALSE)