Rails - List of datatypes for ActiveRecord

  • :string - is for small data types such as a title. (Should you choose string or text?)
  • :text - is for longer pieces of textual data, such as a paragraph of information
  • :binary - is for storing data such as images, audio, or movies.
  • :boolean - is for storing true or false values.
  • :date - store only the date
  • :datetime - store the date and time into a column.
  • :time - is for time only
  • :timestamp - for storing date and time into a column.(What's the difference between datetime and timestamp?)
  • :decimal - is for decimals (example of how to use decimals).
  • :float - is for decimals. Note: Never use float datatype for currency, use decimal. Basically, it stores sign, fraction and exponent to represent a float. Use float when you don't care about precision too much e.g. latitude/longitude values etc. Use decimal always, when precision is required. e.g. numbers that need to be precise and add up correctly (like compounding interest and currency related calculations)
  • :integer - is for whole numbers.
  • :primary_key - unique key that can uniquely identify each row in a table

There's also references used to create associations. But, I'm not sure this is an actual data type.

New Rails 4 datatypes available in PostgreSQL:

  • :hstore - storing key/value pairs within a single value (learn more about this new data type)
  • :array - an arrangement of numbers or strings in a particular row (learn more about it and see examples)
  • :cidr_address - used for IPv4 or IPv6 host addresses
  • :inet_address - used for IPv4 or IPv6 host addresses, same as cidr_address but it also accepts values with nonzero bits to the right of the netmask
  • :mac_address - used for MAC host addresses

Learn more about the address datatypes here and here.

Also, here's the official guide on migrations: http://edgeguides.rubyonrails.org/migrations.html

Useful link: https://stackoverflow.com/questions/17918117/rails-4-list-of-available-datatypes