Session must be bound error using Squeryl

Question

Update: Okay, I fixed the problem I was having, but I'm still not quite sure what I was doing wrong. In any case, I wrote the following method in IRCDB:

def tryit[T](p: => T) = {
    Class.forName("org.h2.Driver") //what's the point in this...?

    SessionFactory.concreteFactory = Some(() =>
        Session.create(java.sql.DriverManager.getConnection("jdbc:h2:~/irc","ScalaIRC",""), new H2Adapter))

    transaction {
        p
    }
}

Then used it like so:

 val query = from(IRCDB.channels)(c => select(c))
 IRCDB.tryit {
     for (r <- query) println("chan: " + r.name)
 }

And it now works. From my understanding, I believed that once the session was created using the SessionFactory, I'd be able to use transaction { ... } anywhere that has the proper import. Apparently, my understanding is incorrect.

If anyone has anything to add please do.

---

So, I just started using Squeryl for a project I'm working on so this might just be an oversight on my part. So, first the code:

I have the following imports:

import org.squeryl.PrimitiveTypeMode._
import java.sql.Timestamp
import java.sql.DriverManager
import java.util.Date
import org.squeryl.adapters.H2Adapter
import org.squeryl.dsl.{OneToMany, ManyToOne, CompositeKey2}
import org.squeryl._

I have the following table defined:

class ChannelTable(val id: Long, val name : String,
               val p_mode : Boolean, val s_mode : Boolean,
               val i_mode : Boolean, val t_mode : Boolean,
               val n_mode : Boolean, val m_mode : Boolean,
               val key : Option[String]) extends KeyedEntity[Long] {
    def this() = this(0,"", false, false, false, false, false, false, Some(""))

    lazy val bans:OneToMany[ChannelBanTable] = IRCDB.channelToChanBans.left(this)
    lazy val users = IRCDB.channelUsers.left(this)
    lazy val invites = IRCDB.channelInvites.left(this)
}

And the following Schema defined:

object IRCDB extends Schema {
    val channels = table[ChannelTable]

    on(channels)(c => declare(
      c.p_mode defaultsTo(false),
      c.s_mode defaultsTo(false),
      c.i_mode defaultsTo(false),
      c.t_mode defaultsTo(false),
      c.n_mode defaultsTo(false),
      c.m_mode defaultsTo(false),
      c.name is(unique, indexed)
    ))

    def init {
        Class.forName("org.h2.Driver") //what's the point in this...?

        SessionFactory.concreteFactory = Some(() =>
          Session.create(DriverManager.getConnection("jdbc:h2:~/irc","ScalaIRC",""), new H2Adapter))
    }
    def getAllChannels = transaction { from(channels)(c => select(c))}
}

I have been able to insert into the table with the following at the Console:

scala> import db._;import org.squeryl.PrimitiveTypeMode._
import db._
import org.squeryl.PrimitiveTypeMode._
scala> IRCDB.init
scala> transaction { IRCDB.channels.insert(new ChannelTable(0,"#chan_name", false, false, false, false, false, false, None)) }
res3: db.ChannelTable = db.ChannelTable@4

I can confirm with the H2 Console that this does indeed occur. However, when I call IRCDB.getAllChannels (in both the Scala Console and in code) I get the following error:

java.lang.RuntimeException: no session is bound to current thread, a session must be created via Session.create 
and bound to the thread via 'work' or 'bindToCurrentThread'
    at scala.Predef$.error(Predef.scala:58)
    at org.squeryl.Session$$anonfun$currentSession$1.apply(Session.scala:117)
    at org.squeryl.Session$$anonfun$currentSession$1.apply(Session.scala:117)
    at scala.Option.getOrElse(Option.scala:59)
    at org.squeryl.Session$.currentSession(Session.scala:116)
    at org.squeryl.dsl.AbstractQuery.org$squeryl$dsl$AbstractQuery$$_dbAdapter(AbstractQuery.scala:136)
    at org.squeryl.dsl.AbstractQuery$$anon$1.<init>(AbstractQuery.scala:140)
    at org.squeryl.dsl.AbstractQuery.iterator(AbstractQuery.scala:138)
    at scala.collection.IterableLike$class.foreach(IterableLike.scala:79)
    at org.squeryl.dsl.AbstractQuery.foreach(AbstractQuery.scala:27)
    at scala.collection.TraversableLike$class.map(TraversableLike.scala:206)
    at org.squeryl.dsl.AbstractQuery.map(AbstractQuery.scala:27)
    at scala.runtime.ScalaRunTime$.inner$1(ScalaRunTime.scala:255)
    at scala.runtime.ScalaRunTime$.stringOf(ScalaRunTime.scala:258)
    at RequestResult$line7$object$.<init>(<console>:12)
    at RequestResult$line7$object$.<clinit>(<console>)
    at RequestResult$line7$object.scala_repl_result(<console>)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at scala.tools.nsc.Interpreter$Request$$anonfun$loadAndRun$1$$anonfun$apply$18.apply(Interpreter.scala:981)
    at scala.tools.nsc.Interpreter$Request$$anonfun$loadAndRun$1$$anonfun$apply$18.apply(Interpreter.scala:981)
    at scala.util.control.Exception$Catch.apply(Exception.scala:79)
    at scala.tools.nsc.Interpreter$Request$$anonfun$loadAndRun$1.apply(Interpreter.scala:980)
    at scala.tools.nsc.Interpreter$Request$$anonfun$loadAndRun$1.apply(Interpreter.scala:980)
    at scala.util.control.Exception$Catch.apply(Exception.scala:79)
    at scala.tools.nsc.Interpreter$Request.loadAndRun(Interpreter.scala:979)
    at scala.tools.nsc.Interpreter.loadAndRunReq$1(Interpreter.scala:578)
    at scala.tools.nsc.Interpreter.interpret(Interpreter.scala:597)
    at scala.tools.nsc.Interpreter.interpret(Interpreter.scala:575)
    at scala.tools.nsc.InterpreterLoop.reallyInterpret$1(InterpreterLoop.scala:471)
    at scala.tools.nsc.InterpreterLoop.interpretStartingWith(InterpreterLoop.scala:514)
    at scala.tools.nsc.InterpreterLoop.command(InterpreterLoop.scala:361)
    at scala.tools.nsc.InterpreterLoop.processLine$1(InterpreterLoop.scala:242)
    at scala.tools.nsc.InterpreterLoop.repl(InterpreterLoop.scala:248)
    at scala.tools.nsc.InterpreterLoop.main(InterpreterLoop.scala:558)
    at scala.tools.nsc.InterpreterLoop.main(InterpreterLoop.scala:609)
    at org.jetbrains.plugins.scala.compiler.rt.ConsoleRunner.main(ConsoleRunner.java:33)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:115)

I don't understand why I would be getting this error if I was able to insert rows into the table doing nearly the same way. If I try to execute transaction { from(IRCDB.channels)(c => select(c)) } at the Console I get the same error.

---

Edit: I've added the full stack trace. Also, I rewrote the getAllChannels function like this:

def getAllChannels = transaction { 
  val ret = from(channels)(c => select(c))
  println("sql: " + ret)
  ret
}

I still receive an error, but it does print the query out first -- I thought this may be useful:

sql: 'QueryExpressionNode[root:1a0d111]:rsm='ResultSetMapper:fdf48d()--
    'FieldSelectElement:ChannelTable1_name
        org.squeryl.dsl.ast.FieldSelectElement$$anon$3
    'FieldSelectElement:ChannelTable1_i_mode
        org.squeryl.dsl.ast.FieldSelectElement$$anon$3
    'FieldSelectElement:ChannelTable1_s_mode
        org.squeryl.dsl.ast.FieldSelectElement$$anon$3
    'FieldSelectElement:ChannelTable1_key
        org.squeryl.dsl.ast.FieldSelectElement$$anon$3
    'FieldSelectElement:ChannelTable1_n_mode
        org.squeryl.dsl.ast.FieldSelectElement$$anon$3
    'FieldSelectElement:ChannelTable1_m_mode
        org.squeryl.dsl.ast.FieldSelectElement$$anon$3
    'FieldSelectElement:ChannelTable1_id
        org.squeryl.dsl.ast.FieldSelectElement$$anon$3
    'FieldSelectElement:ChannelTable1_t_mode
        org.squeryl.dsl.ast.FieldSelectElement$$anon$3
    'FieldSelectElement:ChannelTable1_p_mode
        org.squeryl.dsl.ast.FieldSelectElement$$anon$3
    'ViewExpressionNode[sample:ChannelTable[16e3f87]]:rsm='ResultSetMapper:442b95($(1->ChannelTable.name:java.lang.String),$(2->ChannelTable.i_mode:java.lang.Boolean),$(3->ChannelTable.s_mode:java.lang.Boolean),$(4->ChannelTable.key:Option[java.lang.String]),$(5->ChannelTable.n_mode:java.lang.Boolean),$(6->ChannelTable.m_mode:java.lang.Boolean),$(7->ChannelTable.id:java.lang.Long),$(8->ChannelTable.t_mode:java.lang.Boolean),$(9->ChannelTable.p_mode:java.lang.Boolean))--*

Select
  ChannelTable1.name as ChannelTable1_name,
  ChannelTable1.i_mode as ChannelTable1_i_mode,
  ChannelTable1.s_mode as ChannelTable1_s_mode,
  ChannelTable1.key as ChannelTable1_key,
  ChannelTable1.n_mode as ChannelTable1_n_mode,
  ChannelTable1.m_mode as ChannelTable1_m_mode,
  ChannelTable1.id as ChannelTable1_id,
  ChannelTable1.t_mode as ChannelTable1_t_mode,
  ChannelTable1.p_mode as ChannelTable1_p_mode
From
  ChannelTable ChannelTable1
java.lang.RuntimeException: no session is bound to current thread, a session must be created via Session.create 
and bound to the thread via 'work' or 'bindToCurrentThread'
    at scala.Predef$.error(Predef.scala:58)
    at org.squeryl.Session$$anonfun$currentSession$1.apply(Session.scala:117)
    at org.squeryl.Session$$anonfun$currentSession$1.apply(Session.scala:117)
    at scala.Option.getOrElse(Option.scala:59)
    at org.squeryl.Session$.currentSession(Session.scala:116)
    at org.squeryl.dsl.AbstractQuery.org$squeryl$dsl$AbstractQuery$$_dbAdapter(AbstractQuery.scala:136)
    at org.squeryl.dsl.AbstractQuery$$anon$1.<init>(AbstractQuery.scala:140)
    at org.squeryl.dsl.AbstractQuery.iterator(AbstractQuery.scala:138)
    at scala.collection.IterableLike$class.foreach(IterableLike.scala:79)
    at org.squeryl....

Answer 1

Here's what I suspect, your method :

def getAllChannels = transaction { from(channels)(c => select(c))}

is returning an unevaluated query, i.e. the return type of

from(channels)(c => select(c))

is Query[ChannelTable] so the method returns, the transaction is ended, the console tries to print it, which triggers an evaluation :

at org.squeryl.dsl.AbstractQuery.map(AbstractQuery.scala:27)        
at scala.runtime.ScalaRunTime$.inner$1(ScalaRunTime.scala:255)
at scala.runtime.ScalaRunTime$.stringOf(ScalaRunTime.scala:258)
at RequestResult$line7$object$.<init>(<console>:12)
at RequestResult$line7$object$.<clinit>(<console>)
at RequestResult$line7$object.scala_repl_result(<console>)

since the transaction is ended, you get the message you are getting.

Try this :

def getAllChannels = transaction { 
  val q = from(channels)(c => select(c))
  for(z <- q) {
    println(z)
  }
}