How get data on iOS app with comma in database

Hello I have data in database as type String and it's a number with comma like 20,5. However I dont get result on my app; only when I change the comma by point like 20.5 in database; then I get data.

I use this in my iOS app:

ell.labelPriceCell.text = String(aProduct2.Verkoopprijs)

Anyone can make that 20,5 will be displayed on the app?