Ruby-on-rails – the best method of handling currency/money

currencyrubyruby-on-rails

I'm working on a very basic shopping cart system.

I have a table items that has a column price of type integer.

I'm having trouble displaying the price value in my views for prices that include both Euros and cents. Am I missing something obvious as far as handling currency in the Rails framework is concerned?

Best Answer

You'll probably want to use a DECIMAL type in your database. In your migration, do something like this:

# precision is the total number of digits
# scale is the number of digits to the right of the decimal point
add_column :items, :price, :decimal, :precision => 8, :scale => 2

In Rails, the :decimal type is returned as BigDecimal, which is great for price calculation.

If you insist on using integers, you will have to manually convert to and from BigDecimals everywhere, which will probably just become a pain.

As pointed out by mcl, to print the price, use:

number_to_currency(price, :unit => "€")
#=> €1,234.01

Related Solutions

Ruby-on-rails – the easiest way to duplicate an activerecord record

To get a copy, use the clone (or dup for rails 3.1+) method:

# rails < 3.1
new_record = old_record.clone

#rails >= 3.1
new_record = old_record.dup

Then you can change whichever fields you want.

ActiveRecord overrides the built-in Object#clone to give you a new (not saved to the DB) record with an unassigned ID.
Note that it does not copy associations, so you'll have to do this manually if you need to.

Rails 3.1 clone is a shallow copy, use dup instead...

C# – the best data type to use for money in C#

As it is described at decimal as:

The decimal keyword indicates a 128-bit data type. Compared to floating-point types, the decimal type has more precision and a smaller range, which makes it appropriate for financial and monetary calculations.

You can use a decimal as follows:

decimal myMoney = 300.5m;

Best Answer

Related Solutions

Ruby-on-rails – the easiest way to duplicate an activerecord record

C# – the best data type to use for money in C#

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