Programming Ecto

Adding Custom Types Without the Built-In Types

So far, the custom types we’ve created have been built on the types already included in Ecto. By adding a layer on top of a built-in type, we can have richer data types in our Elixir code than we’d have just using the standard database types.

However, if you want to work with a data type that is not currently supported in Ecto, you’ll need to go a little deeper and write your own driver extension. To better understand how that might work, let’s take a closer look at how data moves from your Elixir code to the database and back, as shown in this figure:

We start at the database, where the raw data ...