Calculation of costs in relation to exchange rates

[DimaMD]

Hello everybody

I have 2 tables, Costs and Exchange Rates
The cost table is
- Date
-Costs
-Currency
In the table Exchange rates are
-Date
-Currency
-Exchange rate

My task is to figure out the costs of the exchange rate. I managed to transfer exchange rates to the cost table in the expense table, but there was a problem with the "UAH" exchange rate. 
This exchange rate is only available for one date
What do I need to change to get this exchange rate?

File exempl

[DimaMD · Accepted solution]

I found a solution to my problem on my own
 

Стовпець = IF(ISBLANK([Exchange rate]),[Costs],[Costs uah])