Here the first value is the price received from a sales, the second is the purchase price. I want to work out the profit or loss. Does this look right? The values that I'm getting back I know are wrong. I've only recently started using Qlik so not very familiar with expressions.
Do you mean summing 2 or more columns in the model either at load or expression , if so then
use RangeSum() e.g. RangeSum(2,3,4,6) = 15 or RangeSum(Col1,Col2,Col3) etc plenty of content in the Help
I have never put a symbol in the field name like you have done.
sum(SalesValue) - sum(PurchaseValue)
Calculate profit in your Loader rather than on the fly as this will impede performance on a large data set on your
More often than not , you source data will probably have pre calculated profit.