Question

I am testing(trying) squeryl’s relations modeling feature

class Foo(val id: Long, val foBar: Long) extends KeyedEntity[Long]{
    //Many Foo's can have one Bar.
    lazy val fbar: ManyToOne[Bar] = myschema.barToFoo.right(this)
}
class Bar(val id: Long) extends KeyedEntity[Long]{
    //One Bar can be assigned to many Foo's.
    lazy val bfoo: OneToMany[Foo] = myschema.barToFoo.left(this)
}

object myschema extends Schema{
    val bars= table[Bar]
    val foo= table[Foo]
    val barToFoo =
        oneToManyRelation(Bar, Foo).
        via((b,f) => b.id === f.foBar)
    /** Find all Bars that are assigned to at least one foo.*/
    def findBars() ={
        from(bars)((b) => where(b.bfoo.size gt 0) select(b))
    }
}

If I try to test that code with the following code:

test("Test findBars"){
  using(jdbcSession){
      val mybars = telemetria.findBars
      for{i <- mybars}{
          println(i.id)
          i.id should equal(1)
      }
  } 
}

And I get the following error:

java.util.NoSuchElementException: None.get

The exception is being thrown from the body of findBars. I can’t think about anything that could be causing such problem. Have anyone run into a similar situation?

Since Daniel pointed out that it could be a compiling problem, I am appending the build.properties and a property from project.scala

project.organization=org.simepar
project.name=scalatra-sbt-prototype
sbt.version=0.7.4
project.version=2.0.0.M2
def.scala.version=2.8.1
build.scala.versions=2.8.1
project.initialize=false

;

val squeryl = "org.squeryl" % "squeryl_2.8.0" % "0.9.4-RC3"

Answer 1

The problem lies in the where clause :
where(b.bfoo.size gt 0)

b.bfoo.size causes an implicit conversion of the bfoo Query to an Iterable
(b.bfoo is a OneToMany[Foo] which is also a Query[Foo], calling
.size on it cause the evaluation of the query).

You need to rewrite “findBars” like this :

def findBars =

  from(bars)(b =>
    where(b.id in
              from(foo)(f=> where(f.foBar === b.id) select(f.foBar))
    )
    select(b)
  )