ruby on rails - Storing arrays in database using ActiveRecord

Question

I am on rails 2.3.8 & I am using mysql as db adapter. I want to store arrays in my database. After searching I could come up with this very useful article.

Now I need to use GUI for input & not only server console. So say I have a text field called nums which logically should have int array. What should be the format of nums so that it becomes easy to retrieve & store the array out of that string ?

Answer 1

If you use serialize then you shouldn't have to worry about how the data is stored within the text field, although it's actually YAML.

serialize is documented in the Rails/ActiveRecord API (scroll down to the section headed "Saving arrays, hashes, and other non-mappable objects in text columns")

For display, you need a format that is understandable to users and that can be easily converted back into an array in your code. Comma- or space-delimited?

Formatting for output:

delim = ',' # or ' ' for spaces, or whatever you choose
array.join(delim)

Converting back into an array might work as follows:

num_array = nums.split(delim).map(&:to_i) # or to_f if not integers

or perhaps using String#scan?

num_array = nums.scan(/d+/).map(&:to_i) # for positive integers