具有DAX公式的Power BI动态列参考

Question

I have a Orders and ExchangeRates tables connected via a date key:

What I am trying to do is to fetch the correct currency exchange rate from ExchangeRates , which are organized in columns, with the column name matching the currency codes from Orders .

I'm basically trying to make a dynamic column reference to the EUR or JPY columns by using the matching Orders[orderCurrency] like this:

orderExchangeRate = LOOKUPVALUE(ExchangeRates[Orders[orderCurrency]],
ExchangeRates[date],Orders[date])

or:

orderExchangeRage = SELECTCOLUMNS(ExchangeRates,Orders[orderCurrency], ....)

But none of the functions accept a dynamic column reference, they expect the actual name of the column

How can I dynamically refer to the EUR and JPY columns based on Orders[orderCurrency] ? Isn't there something similar to INDIRECT to make a dynamic reference in PowerBI?

Answer 1

As far as I know, there is no such function as INDIRECT in DAX.

You have (at least) two options:

• If it's just EUR and JPY, you could create two formulas and based on the currency switch between them with IF() or SWITCH(). Like: If (Currency = "EUR", LOOKUPVALUE(EUR), LOOKUPVALUE(JPY). Pseudo code, of course.

• Unpivot the EUR and JPY column in the ExchangeRate table. Then you'll have a line for each date and currency, and you can reference it as you like. Especially usefull with more currency combinations. You can Unpivot in the Query Editor, Transformation Tab.