I'm trying to use Squeryl to take the contents of a table from one database, and append it to the equivalent table in another database. The primary key will have to be reassigned in the process, but I'm getting the error NULL not allowed for column "SIMID". Why is this?

object Concatenator {
  def main(args: Array[String]) {
    Class.forName("org.h2.Driver");

    val seshA = Session.create(
      java.sql.DriverManager.getConnection("jdbc:h2:file:data/resultsA", "sa", "password"),
      new H2Adapter
    )

    val seshB = Session.create(
      java.sql.DriverManager.getConnection("jdbc:h2:file:data/resultsB", "sa", "password"),
      new H2Adapter
    )

    using(seshA){
      import Library._
      from(sims){s => select(s)}.foreach{item =>
        using(seshB){
          sims.insert(item);
        }
      }
    }

  }

  case class Simulation(
    @Column("SIMID")
    var id: Long, 
    val date: Date
  ) extends KeyedEntity[Long]

  object Library extends Schema {
    val sims = table[Simulation]

    on(sims)(s => declare(
      s.id is(unique, indexed, autoIncremented)
    ))
  }
}