Brians200/CIS560 — comment on commit 8598109856f80e1f584707a1953c0d4d035a6691
File: grails-app/controllers/cis560/PortfolioController.groovy line 74
By Brians200:

Think about what the type of currentQuantity is. Subtraction is not defined for a ResultSet. You need to call something like currentQuantity.getInt(1)