Programming Ecto

Chapter 10Creating and Using Custom Types

In Chapter 3, ​Connecting Your Tables to Elixir Structs with Schemas​, we learned about the data types Ecto provides for creating schemas. Ecto uses these data types to translate values expressed in Elixir code into values that a database can store. A String value in Elixir, for example, becomes a VARCHAR when stored in a MySQL table.

Most of the time, Ecto’s built-in data types will give you everything you need. But there may be times when you want to use a data type that’s not directly supported by Ecto. For these cases, Ecto provides a mechanism for defining your own custom types. By implementing just a few functions, you can add support for storing any data type in your database.

In this chapter, ...