Compare two person columns in a list

Question

I have a list which has a "Person or Group" column called as Reviewer. I want to notify the reviewers whenever he/she is added to the list item.

I created a custom workflow which sends a mail on item creation to reviewers. However, when an item is edited i want that if a person was already there as a reviewer, skip him. If he/she is newly added, send him a mail.

The way I was trying was that, I created a second column named as Reviewer1 and am trying to compare the two columns Reviewer and Reviewer1. If someone exists in Reviewer1 and not in Reviewer, send him a mail. Can someone please help to compare the two columns?

Answer 1

I think, that shouldn't be possible with OOB. You have to write workflow activity for comparing user in User field with Current User or user in another field.

And apply that workflow activity to the workflow by using SharePoint Designer / Visual Studio.

Answer 2

I'm pretty sure you could do this OOTB with Sharepoint Designer.

You have the Reviewer field and the Reviewer1, you create a workflow that fires on both created and changed.

I made an example in SPD:

Edit: Looks like you are maybe looking for multiple people or group field, then this solution would not work btw.

Answer 3

I have had the same problem trying to get a SharePoint 2010 workflow to send a email to a "AssignedTo" "Person or Group" when only that field changed. It was solved it by creating a hidden column to store the previous value of "AssignedTo" and creating workflow variables and assigning them, as type "string", to each People/Group item to be compared. Then just compare the workflow variables.

See the screen capture below (including debug log messages):