Please note this is a work in progress, use it at your own risk

Anorm PG Entities

Anorm provides a great way to talk with a SQL database. It allows for great liberty when writing SQL and provide rather nice ways of parsing results. Anorm doesn't suffer from the issues common with ORMs: you're able to write efficient SQL tailored to the database you use, and you're not forced to use a poorly and automatically designed DB schema.

Basically, DB-agnostic ORMs prevent you from correctly using your SQL DB. Anorm doesn't. It's not as type safe as other solutions, but it's a sweet spot between safety and flexibility.

Unfortunately, anorm requires you to write quite a lot of boilerplate. Having to type every single SQL query / command is bothersome and error-prone.

Anorm PG Entities is designed to free you from the boilerplate (provided you use Postgresql, but you already are, aren't you?) by abstracting away the field list (no more SELECT *) and RowParser[A], thus allowing you to focus on your queries structure, not minutiae. For the simple cases, Anorm PG Entities generates all the SQL for you.

Unlike other tools, Anorm PG Entities separates your model from the mapping to the database, which gives you flexibility. No need to put annotations everywhere, you can override everything you want.

Using it

Anorm PG Entities is published for scala 2.11

resolvers += "Clever Cloud Repository" at "http://maven.clever-cloud.com"

libraryDependencies += "name.delafargue" %% "anorm-pg-entity" % "0.1-SNAPSHOT"

Show me the code

For now you have to write the PgEntity instance yourself. Don't worry, it's almost boilerplate-free.

Automagic instance derivation is in the works. Stay tuned.

Regular use

import pgentity._

// Data Definition

case class DummyTable(
  id: UUID, // Please refrain from using sequential IDs :-)
  name: String,
  number: Int
)

object FunStuff {
  // Minimal boilerplate

  implicit val DummyTablePgEntity = new PgEntity[DummyTable] {
    // The name of the table
    val tableName = "dummy_table"

    // The columns
    val columns = List(PgField("dummy_table_id", Some("UUID")), PgField("name"), PgField("number"))

    // The parser
    def parser(prefix: String) = {
      get[UUID](prefix + "dummy_table_id") ~
      str(prefix + "name") ~
      int(prefix + "number") map { case (id ~ name ~ number) => DummyTable(id, name, number) }
    }
  }

  // Enjoy

  val values = DB.withConnection { implicit c =>
      SQL(selectSQL[DummyTable]).as(parser[DummyTable]().*).toList
  }
}

Automagic use

Work in progress

The idea is to use shapeless.Generic to automatically derive the PgEntity instance from a case class.

Since I'm a total newbie wrt shapeless, I rely heavily on the patience of @skaalf and a few others (@milessabin, @mandubian, and @alexarchambault).

Build

sbt compile

Please note that anorm PG Entities depends on scala-sql-parser for the tests only.

Scala-SQL-Parser is not released on a repo yet, you have to publish-local it beforehand.

CleverCloud / anorm-pg-entity