Looser coupling with type classes

So far, we have been reading and writing simple types to the database. Let's imagine that we want to add a gender column to our database. We will store the gender as an enumeration in our physicists database. Our table is now as follows:

mysql> CREATE TABLE physicists (
        id INT(11) AUTO_INCREMENT PRIMARY KEY,
        name VARCHAR(32) NOT NULL,
        gender ENUM("Female", "Male") NOT NULL
);

How can we represent genders in Scala? A good way of doing this is with an enumeration:

// Gender.scala

object Gender extends Enumeration {
  val Male = Value
  val Female = Value
}

However, we now have a problem when deserializing objects from the database: JDBC has no built-in mechanism to convert from a SQL ENUM type to a Scala Gender type. ...

Get Scala for Data Science now with the O’Reilly learning platform.

O’Reilly members experience live online training, plus books, videos, and digital content from nearly 200 publishers.