[OPEN-ILS-GENERAL] Currency Exchange Rate Questions

[Sean Sutherland]

Thanks Dan,

So, from your observations, a currency rate can be edited; however, the
edit is effective immediately and the previous rate no longer exists
(thus cannot be viewed). In addition, any invoices posted after the rate 
change are unable to use a previous rate.

Sean

> 
> After perusing the acquisitions documentation, I have a few questions
>  regarding currency exchange rates:
> 
> 1. Since exchange rates are constantly in flux, is it possible to 
> edit the effective dates of a currency's exchange rate?
> 
> This doesn't appear to be possible at the database level; the table 
> that contains exchange rates simply has the "from" currency, the "to"
>  currency, and a ratio. There's no concept of dates as far as 
> exchange rates goes.
> 
> 2. Is there a way to view a currency's exchange rates for a given 
> date range?
> 
> Not natively within Evergreen right now. I suspect the best way to do
>  this would be to use a tool like 
> http://finance.yahoo.com/currency-converter/#from=USD;to=EUR;amt=1 to
>  track exchange rates, rather than trying to turn Evergreen into a 
> foreign exchange rate tracking tool.
> 
> 3. What date is used to calculate the exchange on a given 
> transaction?
> 
> Poking at the database schema and some of the code again, it looks 
> like the exchange rate is calculated when the fund is debited for a 
> lineitem. The acq.fund_debit table holds origin_amount, 
> origin_currency, and amount columns, so you could work backwards to 
> see what rate was used when that debit was calculated.
> 
> The exchange rate is also calculated when you transfer amounts from 
> one fund to another fund and the funds have different currency types.