multiple currencies in a single table - mysql

Question

How to make a MySQL table that could contain multiple type of currencies ($, Euros, ...) ? And if I want to make a final report is their a way to make a sum of those currencies other than adding multiple if statements to the sum ?

Answer 1

There may be several aspects involved. So here is some brainstorming:
You offer the same product in different currencies, e.g. a toy for 10 EUR or 11 USD. So you'd probably have an item table plus an item_price table, where the latter has product number, currency and price. (An alternative would be to have just one price, e.g. in USD and a currency table with conversion rates and you'd calculate the foreign price. But then you'd get "ugly" prices, e.g. 10.57, rather than typical prices like 10.50, 10.90 or 10.99. But well, you could have a price adjustment funtion for that, too. And you'd have to keep your conversion tables up-to-date or live with possible losses.)
A customer buys products and pays the bill. The bill is in one currency (store price and currency in the bill), but you also get your money in your currency, as PayPal or the bank convert it at a daily rate. Do you need to store this real amount, too? Then that would be another column in your bill.
I don't know how it is about taxes. Different currencies sounds like different countries. Maybe you'd have to deal with these in your database, too. I just don't know. The prices you show and store are usually gross prices (the price a customer actually pays) and the taxes (could be different VAT percentages with different products in one single bill) would have to be calculated.
As to getting sums: with all the information stored you'd get them with joins from the tables. No if-then-else in my opinion.

Answer 2

As per my opinion you can create a Country Table which contains
CountryID, CountryName, CurrencyCode, ExchangeRate. Now In that
country table you have to add all countries which you want to add but
you have to keep one thing in mind that you have to decide 1 currency
as base currency and put exchangeRate as 1 for that currency and
convert all other currencies exchangeRate based on the base currency
and insert into that table. i.e. Keep base currency as USD so insert
1 record with USD and exchangeRate must be 1 for that currency.
Suppose I am adding India as country than exchangeRate for that
country is based on USD as 66.40 Rs. insert all other countries
according to this entries.
Now when you want to add any transaction related to money in any
table then keep exchangeRate column with that amount column. ind
insert the exchangeRate and amount same as user's currency. i.e. If
my user is in India country, so it's currency is INR. Now that user
wants to add 1000 Rs. then you have to enter that 1000 Rs amount in
transaction table as it is without any conversion with exchange Rate
of 66.40 (fetch from country table). Same way If user currency is USD
and he wants to add a transaction of 100$ than store 100 as Amount
and exchangeRate as 1.
Now when you want to create any reports then just divide exchangeRate
with Amount, so you will get report in your base currency and after
conversion in base currency you can generate each report in any
currency as per your requirement.