Scala-Play-Slick-Demo/modules/api/src/main/scala/com/example/services/TaskLibraryService.scala

package com.example.services

import monix.eval.Task
import com.example.models.Book
import com.example.models.Author
import com.example.models.NewAuthor
import com.example.models.NewBook

trait TaskLibraryService {
  // Simple function that returns a book
  def findBookById(id: Long): Task[Option[Book]]

  // Simple function that returns a list of books with it's author
  def findBooksWithAuthor: Task[Seq[(Book, Author)]]

  // Insert a book and an author composing two DBIOs in a transaction
  def insertBookAndAuthor(book: NewBook, author: NewAuthor): Task[(Long, Long)]

  def getAuthorsForBook(id: Long): Task[Seq[(Author, Book)]]
}