Slick in Scala

 Slick in Scala

Slick is a database access library for Scala that provides a typesafe DSL for querying databases. It allows you to define database schemas and perform CRUD operations using a Scala API that feels natural and intuitive. Here's an example of defining a simple database schema and querying it

import slick.jdbc.SQLiteProfile.api._

case class User(id: Option[Int], name: String, email: String)

class UsersTable(tag: Tag) extends Table[User](tag, "users") {

  def id = column[Int]("id", O.PrimaryKey, O.AutoInc)

  def name = column[String]("name")

  def email = column[String]("email")

  def * = (id.?, name, email) <> (User.tupled, User.unapply)

}

val db = Database.forConfig("sqlite")

val users = TableQuery[UsersTable]

val setupAction = DBIO.seq(users.schema.create)

val setupFuture = db.run(setupAction)

val insertAction = DBIO.seq(

  users += User(None, "Alice", "alice@example.com"),

  users += User(None, "Bob", "bob@example.com")

)

val insertFuture = db.run(insertAction)

val queryAction = users.result

val queryFuture = db.run(queryAction)

queryFuture.onSuccess {

  case userSeq => userSeq.foreach(println)

}

In this example, a User case class is defined to represent the users table, and a UsersTable class is defined to map the table to the case class using Slick's DSL. A database connection is established using Slick's Database object, and a TableQuery object is created to represent the UsersTable. A setup action is defined to create the table schema, and an insert action is defined to insert two rows into the table. Finally, a query action is defined to retrieve all rows from the table, and the query is executed using db.run. When the query completes successfully, the result is printed to the console.