Programming :: Duplicate Value In Select - Mysql Query ?

Trying to export a Mysql query to a .csv file the query draws from multiple tables, e.g. sales, purchase and currency

Code:

What i'm trying to do is to export both the sales and purchase to a single line where both the currency for the sales and the purchase is specified.

Basically like this:

Code:

Problem here is that i'm stating currency.value twice in the same select and don't know how to define which currency.value applies to sales and which to purchase.