use sqlu 
this demo  work
case ("insertOnDuplicateKey",answers:List[Answer])=>{
  def buildInsert(r: Answer): DBIO[Int] =
    sqlu"insert into answer (aid,bid,sbid,qid,ups,author,uid,nick,pub_time,content,good,hot,id,reply,pic,spider_time) values (${r.aid},${r.bid},${r.sbid},${r.qid},${r.ups},${r.author},${r.uid},${r.nick},${r.pub_time},${r.content},${r.good},${r.hot},${r.id},${r.reply},${r.pic},${r.spider_time}) ON DUPLICATE KEY UPDATE `aid`=values(aid),`bid`=values(bid),`sbid`=values(sbid),`qid`=values(qid),`ups`=values(ups),`author`=values(author),`uid`=values(uid),`nick`=values(nick),`pub_time`=values(pub_time),`content`=values(content),`good`=values(good),`hot`=values(hot),`id`=values(id),`reply`=values(reply),`pic`=values(pic),`spider_time`=values(spider_time)"
  val inserts: Seq[DBIO[Int]] = answers.map(buildInsert)
  val combined: DBIO[Seq[Int]] = DBIO.sequence(inserts)
  DEST_DB.run(combined).onComplete(data=>{
    println("insertOnDuplicateKey data result",data.get.mkString)
    if (data.isSuccess){
      println(data.get)
      val lastid=answers.last.id
      Sync.lastActor !("upsert",tablename,lastid)
    }else{
      //retry
      self !("insertOnDuplicateKey",answers)
    }
  })
}
and i try to use sqlu in a single sql but error maybe sqlu dont supply String Interpolation
this demo dont work
case ("insertOnDuplicateKeyError",answers:List[Answer])=>{
  def buildSql(execpre:String,values: String,execafter:String): DBIO[Int] = sqlu"$execpre $values $execafter"
  val execpre="insert into answer (aid,bid,sbid,qid,ups,author,uid,nick,pub_time,content,good,hot,id,reply,pic,spider_time)  values "
  val execafter=" ON DUPLICATE KEY UPDATE  `aid`=values(aid),`bid`=values(bid),`sbid`=values(sbid),`qid`=values(qid),`ups`=values(ups),`author`=values(author),`uid`=values(uid),`nick`=values(nick),`pub_time`=values(pub_time),`content`=values(content),`good`=values(good),`hot`=values(hot),`id`=values(id),`reply`=values(reply),`pic`=values(pic),`spider_time`=values(spider_time)"
  val valuesstr=answers.map(row=>("("+List(row.aid,row.bid,row.sbid,row.qid,row.ups,"'"+row.author+"'","'"+row.uid+"'","'"+row.nick+"'","'"+row.pub_time+"'","'"+row.content+"'",row.good,row.hot,row.id,row.reply,row.pic,"'"+row.spider_time+"'").mkString(",")+")")).mkString(",\n")
  val insertOrUpdateAction=DBIO.seq(
    buildSql(execpre,valuesstr,execafter)
  )
  DEST_DB.run(insertOrUpdateAction).onComplete(data=>{
    if (data.isSuccess){
      println("insertOnDuplicateKey data result",data)
      //retry
      val lastid=answers.last.id
      Sync.lastActor !("upsert",tablename,lastid)
    }else{
      self !("insertOnDuplicateKey2",answers)
    }
  })
}
a mysql sync tool with scala slick
https://github.com/cclient/ScalaMysqlSync