What is Slick?

Slick is Typesafe‘s modern database query and access library for Scala. It allows you to work with stored data almost as if you were using Scala collections while at the same time giving you full control over when a database access happens and which data is transferred. You can also use SQL directly.

val limit = 10.0
// Your query could look like this:
( for( c <- coffees; if c.price < limit ) yield ).list
// or this:
sql"select COF_NAME from COFFEES where PRICE < $limit".as[String].list

When using Scala instead of SQL for your queries you profit from the compile-time safety and compositionality. Slick can generate queries for different backends including your own, using its extensible query compiler.

Why Slick? / Features

Slick offers a unique combination of features:


  • Access stored data just like Scala collections
  • Unified session management based on JDBC Connections
  • Supports SQL if you need it
  • Simple setup


  • Scala syntax
  • Fetch results without pain (no ResultSet.getX)

Scales naturally

  • Stateless (like the web)
  • Explicit control of execution time and transferred data


  • No SQL-injections
  • Compile-time safety (types, names, no typos, etc.)
  • Type-safe support for custom database functions


  • It‘s Scala code: abstract and re-use with ease

Slick requires Scala 2.10. (For Scala 2.9 please use ScalaQuery, the predecessor of Slick).

Supported database systems

Other SQL databases can be accessed right away with a reduced feature set. Writing a fully featured plugin for your own SQL-based backend can be achieved with a reasonable amount of work. Support for other backends (like NoSQL) is under development but not yet available.

Quick Overview

Accessing databases using Slick’s lifted embedding requires the following steps.

  1. Add the Slick jar and its dependencies to your project

  2. Pick a driver for a particular db

    import scala.slick.driver.H2Driver.simple._
  3. Describe your Database schema

    class Coffees(tag: Tag) extends Table[(String, Double)](tag, "COFFEES") {
      def name = column[String]("COF_NAME", O.PrimaryKey)
      def price = column[Double]("PRICE")
      def * = (name, price)
    val coffees = TableQuery[Coffees]
  4. Write queries using for-comprehensions or map/flatMap wrapped in a session scope

    Database.forURL("jdbc:h2:mem:test1", driver = "org.h2.Driver") withSession {
      implicit session =>
      ( for( c <- coffees; if c.price < 10.0 ) yield ).list
      // or
      coffees.filter(_.price < 10.0).map(

The next chapter explains these steps and further aspects in more detail.


Slick is released under a BSD-Style free and open source software license.