Get records count

Hi Experts,

In my workflow i have recipients linked to purchase history table 1-n and each purchaseId has many records in items table.Now i want to get count of number of items present for each purchaseId

I have linked purchase table to items table  1-n in enrichment but  i am not able get the count of  items for each each purchaseId.

could any one let me know how to implement this .

@milan_vucetic