Ordering

Start by importing:

import scalaql._

// Docs classes
import scalaql.docs.Hogwarts._

Usually, sorting scala collections is simple, but it looks awkwardly when it comes to descending ordering.
To sort this by age in descending order, you should do the following:

students.sortBy(_.age)(Ordering[Int].reverse)
// res0: List[Student] = List(
//   Student(
//     name = "Harry",
//     age = 19,
//     faculty = "Gryffindor",
//     grade = 85.1,
//     specialization = "getting into troubles",
//     birthDay = 1980-07-31
//   ),
//   Student(
//     name = "Ron",
//     age = 18,
//     faculty = "Gryffindor",
//     grade = 66.2,
//     specialization = "eating",
//     birthDay = 1980-05-01
//   ),
//   Student(
//     name = "Hermione",
//     age = 18,
//     faculty = "Gryffindor",
//     grade = 99.6,
//     specialization = "learning",
//     birthDay = 1979-09-17
//   ),
//   Student(
//     name = "Draco",
//     age = 18,
//     faculty = "Slytherin",
//     grade = 85.1,
//     specialization = "trolling",
//     birthDay = 1980-06-05
//   ),
//   Student(
//     name = "Cedric",
//     age = 17,
//     faculty = "Hufflepuff",
//     grade = 90.1,
//     specialization = "young dying",
//     birthDay = 1977-10-01
//   )
// )

Additionally sorting by name in ascending order looks even more awkwardly:

students.sortBy(s => (s.age, s.name))(Ordering.Tuple2(Ordering[Int].reverse, Ordering[String]))
// res1: List[Student] = List(
//   Student(
//     name = "Harry",
//     age = 19,
//     faculty = "Gryffindor",
//     grade = 85.1,
//     specialization = "getting into troubles",
//     birthDay = 1980-07-31
//   ),
//   Student(
//     name = "Draco",
//     age = 18,
//     faculty = "Slytherin",
//     grade = 85.1,
//     specialization = "trolling",
//     birthDay = 1980-06-05
//   ),
//   Student(
//     name = "Hermione",
//     age = 18,
//     faculty = "Gryffindor",
//     grade = 99.6,
//     specialization = "learning",
//     birthDay = 1979-09-17
//   ),
//   Student(
//     name = "Ron",
//     age = 18,
//     faculty = "Gryffindor",
//     grade = 66.2,
//     specialization = "eating",
//     birthDay = 1980-05-01
//   ),
//   Student(
//     name = "Cedric",
//     age = 17,
//     faculty = "Hufflepuff",
//     grade = 90.1,
//     specialization = "young dying",
//     birthDay = 1977-10-01
//   )
// )

Scala QL simplifies this a lot! Just take a look:

val query = select[Student].orderBy(_.age.desc, _.name)
// query: Query[From[Student], Student] = FROM(Hogwarts::Student) -> ORDER BY(Tuple2[+Int,+String])

query
  .show(truncate = false)
  .run(from(students))
// +--------+---+----------+-----+---------------------+----------+
// |name    |age|faculty   |grade|specialization       |birthDay  |
// +--------+---+----------+-----+---------------------+----------+
// |Harry   |19 |Gryffindor|85.1 |getting into troubles|1980-07-31|
// |Draco   |18 |Slytherin |85.1 |trolling             |1980-06-05|
// |Hermione|18 |Gryffindor|99.6 |learning             |1979-09-17|
// |Ron     |18 |Gryffindor|66.2 |eating               |1980-05-01|
// |Cedric  |17 |Hufflepuff|90.1 |young dying          |1977-10-01|
// +--------+---+----------+-----+---------------------+----------+
//