1
votes

I'm writing a veery simple scala script to connect to Mysql using slick 3.

My build.sbt looks like this:

name := "slick_sandbox"

version := "1.0"

scalaVersion := "2.11.7"

libraryDependencies ++= Seq(
  "com.typesafe.slick" %% "slick" % "3.0.3",
  "org.slf4j" % "slf4j-nop" % "1.6.4",
  "mysql" % "mysql-connector-java" % "5.1.6"

)

application.conf:

Drivder is an intentional mistake; also, I did not provide a db username or password!

mysqldb = {
  url = "jdbc:mysql://localhost/slickdb"
  driver = com.mysql.jdbc.Drivder
  connectionPool = disabled
  keepAliveConnection = true
}

Main.scala

import slick.driver.MySQLDriver.api._ import scala.concurrent.ExecutionContext.Implicits.global

object Main {

  def main(args: Array[String]) {

    // test to see this function is being run; it IS
    println("foobar")

    // I expected an error here due to the intentional
    // mistake I've inserted into application.conf
    // I made sure the conf file is getting read; if I change mysqldb
    // to some other string, I get correctly warned it is not a
    // valid key
    val db = Database.forConfig("mysqldb")

    val q = sql"select u.name from users ".as[String]

    db.run(q).map{ res=>
      println(res)
    }
  }
}

It compiles OK. Now this is the result I see when I run sbt run on the terminal:

felipe@felipe-XPS-8300:~/slick_sandbox$ sbt run
[info] Loading project definition from /home/felipe/slick_sandbox/project
[info] Set current project to slick_sandbox (in build file:/home/felipe/slick_sandbox/)
[info] Compiling 1 Scala source to /home/felipe/slick_sandbox/target/scala-2.11/classes...
[info] Running Main 
foobar
[success] Total time: 5 s, completed Sep 17, 2015 3:29:39 AM

Everything looks deceptively OK; even though I explicitly ran the query on a database that doesn't exist, slick went ahead as if nothing has happened.

What am I missing here?

1

1 Answers

2
votes

Slick runs queries asynchronously. So it just didn't have enough time to execute it. In your case you have to wait for result.

object Main {

  def main(args: Array[String]) {

    println("foobar")

    val db = Database.forConfig("mysqldb")

    val q = sql"select u.name from users ".as[String]

    Await.result(
      db.run(q).map{ res=>
      println(res)
    }, Duration.Inf)
  }
}