Question

I’m trying to multiply value X by value Y with SQL. Value X is located in table A and B is located in table B. I couldn’t find the answer for this.

Table Transactions

ID Transaction_ID Total_Amount
1  001            1200
2  002            1500
3  003            1600

Table Rates

ID Currency_Name Exchange_Rate
1  AUD           1.5
2  SEK           2.0
3  PLN           3.0

The question I’m trying to answer is:

What is the Total_Amount for transaction 001 in SEK (Swedish Crown). So I need to multiply 1200 * 2.0 and display the result.

Answer 1

Edited based on added info

SELECT Total_Amount * Exchange_Rate AS Value 
FROM Transactions, Rates 
WHERE Rates.Currency_Name = 'Sek' and Transaction_id = 001