For the RDD, I originally thought I could use the standard PartTranRpt since it already has RcvHead listed as one of the data sources, but there’s no relationship listed.
That report is really tricky. The data set doesn’t make a lot of sense and its mostly black box. You could try printing T1.PONum and T1.PackSlip on the report just to see if the data you expect exists. And/or printing out the entire RcvHead contents in a separate tablix to see what data is being returned there, if any. If RcvHead is already in the system dataset but without a visible relationship, I would not add a relationship to the RDD. It may not be joined the way you think it is, and adding that relationship might actually prevent it from returning the data.
I saw this thread Report Dataset for MS Report Builder - #10 by ckrusen. If the RDD is a data view and it combines all the tables in the RDD into one dataset (PartTran?), then shouldn’t I be able to just add T1.ReceiptComment in the query and field? Doesn’t work though and the error message doesn’t help either.
Ah I’m so sorry it was my mistake this worked! I was too focused on the query and didn’t realize that I had been dragging the ReceiptComment field to the footer of the page. Once I dragged it to the body it worked. Thank you so much!