ETGFindExchRateHelper.cs

public class ETGFindExchRateHelper
{
    public static ExchRate findExchRate(TransDate _transDate, CurrencyCode _fromCurrency, CurrencyCode _toCurrency = Ledger::find(Ledger::current()).AccountingCurrency)
    {
        ExchangeRateCurrencyPair exchangeRateCurrencyPair;
        ExchRate exchRate;

        select firstonly exchangeRateCurrencyPair
         where exchangeRateCurrencyPair.ExchangeRateType == Ledger::find(Ledger::current()).DefaultExchangeRateType
            && exchangeRateCurrencyPair.FromCurrencyCode == _fromCurrency
            && exchangeRateCurrencyPair.ToCurrencyCode   == _toCurrency;
 
        exchRate = ExchangeRate::findByDate(exchangeRateCurrencyPair.RecId, _transDate).ExchangeRate;

        return exchRate;
    }

    public static ExchRate findExchRateByExchangeRateType(ExchangeRateTypeRecId _exchangeRateType, TransDate _transDate, CurrencyCode _fromCurrency, CurrencyCode _toCurrency = Ledger::find(Ledger::current()).AccountingCurrency)
    {
        ExchangeRateCurrencyPair exchangeRateCurrencyPair;
        ExchRate exchRate;

        select firstonly exchangeRateCurrencyPair
         where exchangeRateCurrencyPair.ExchangeRateType == _exchangeRateType
            && exchangeRateCurrencyPair.FromCurrencyCode == _fromCurrency
            && exchangeRateCurrencyPair.ToCurrencyCode   == _toCurrency;
 
        exchRate = ExchangeRate::findByDate(exchangeRateCurrencyPair.RecId, _transDate).ExchangeRate;

        return exchRate;
    }

}