错误scala:递归值变量需要类型

我有一段代码,应该为每个配置单元表创建数据帧:

for (e <- df_tables) {
    val v(df_tables.indexOf(e)) = hiveObj.sql("select * from database."+ e +" order by event_date")
}

这个 df_tables 是一个数据帧 v 是我为这些数据帧选择的名称数组。

df_tables: Array[org.apache.spark.sql.Row] = Array([conversionevents], [elements], [pageviews], [productviews], [registrations], [sitepromotionclicks])

运行此代码时出现两个错误:

<console>:145: error: recursive value e needs type
                  val v(df_tables.indexOf(e)) = hiveObj.sql("select * from database."+ e +" order by event_date")
                                                                                              ^
<console>:145: error: value v is not a case class constructor, nor does it have an unapply/unapplySeq method
                  val v(df_tables.indexOf(e)) = hiveObj.sql("select * from database."+ e +" order by event_date")