Store Scala Collection Into PostgreSQL using Slick

Read.md

Open PostgreSQL and Create a table student in database student.

CREATE EXTENSION hstore;

CREATE TABLE student (
    id     int,
    name   varchar(254) NOT NULL,
    hobbies  text[],
    marks hstore
);

To use slick-pg in sbt project, add the following to your project file:

libraryDependencies += "com.github.tminglei" %% "slick-pg" % "0.8.1"

To run

sbt run

In this example, we have inserted only Scala List and Map in PostgreSQL table. To insert other types, please go here https://github.com/tminglei/slick-pg.

StudentData.scala

import slick.driver.PostgresDriver
import com.github.tminglei.slickpg._

/**
 * This class has the functionality to store
 * scala collection into postgreSQL
 *
 * For Example:- Suppose you have a table with columns having data types such as hstore(sets of key/value pairs) and Arrays
 *
 * CREATE EXTENSION hstore;
 *
 * CREATE TABLE student (
 * id     int,
 * name   varchar(254) NOT NULL,
 * hobbies  text[],
 * marks hstore
 * );
 *
 * Then you can insert scala list in postgres Array and scala map in postgres hstore using this example.
 * 
 * Here we have used Slick-pg [https://github.com/tminglei/slick-pg] (Slick extensions for PostgreSQL), 
 * which also supports other pg types.
 *
 */
trait MyPostgresDriver extends PostgresDriver
  with PgArraySupport
  with PgHStoreSupport {

  override lazy val Implicit = new ImplicitsPlus {}
  override val simple = new SimpleQLPlus {}

  trait ImplicitsPlus extends Implicits
    with ArrayImplicits
    with HStoreImplicits

  trait SimpleQLPlus extends SimpleQL
    with ImplicitsPlus
}

object MyPostgresDriver extends MyPostgresDriver

import MyPostgresDriver.simple._

/**
 * Student Details
 */
case class Student(
  id: Int,
  name: String,
  hobbies: List[String],
  marks: Map[String, String])

/**
 * Slick mapping of Student
 */
class StudentTable(tag: Tag) extends Table[Student](tag, "student") {
  def id = column[Int]("id", O.PrimaryKey)
  def name = column[String]("name")
  def hobbies = column[List[String]]("hobbies", O.Default(Nil))
  def marks = column[Map[String, String]]("marks")

  def * = (id, name, hobbies, marks) <> (Student.tupled, Student.unapply)
}

/**
 * Trait for RDS database connection details
 */
trait RdsDbDetailsStudent {
  lazy val studentQuery: TableQuery[StudentTable] = TableQuery[StudentTable]
  val db = Database.forURL("jdbc:postgresql://localhost:5432/student", "root", "root",
    null, "org.postgresql.Driver")
}

object StudentData extends Application with RdsDbDetailsStudent {

  val student = Student(1, "Ayush", List("Study", "Coding"), Map("Scala" -> "90", "Java" -> "80", "PHP" -> "0"))
  db.withSession { implicit session =>
    studentQuery += student
  }

  println("storing-----------------")

}

What happens if hobbies is Null, even if I used O.Default(Nil) it throws [SlickException: Read NULL value (null) for ResultSet column ]

getting error
Error: Could not find or load main class

I am facing the same problem for h2 database. Do you have any idea?

I am facing the same problem for h2 database. Do you have any idea?

This slick extension is for postgres. Try running it with a Postgres database