问用scala中的varargs创建groupBy函数

EN

def showGroupByDesc(df: DataFrame, cols: Column*): Unit = {
    df.groupBy(cols).count().sort($"count".desc).show()
  }

overloaded method value groupBy with alternatives:
  (col1: String,cols: String*)org.apache.spark.sql.RelationalGroupedDataset <and>
  (cols: org.apache.spark.sql.Column*)org.apache.spark.sql.RelationalGroupedDataset
 cannot be applied to (Seq[org.apache.spark.sql.Column])

@scala.annotation.varargs
  def groupBy(col1: String, cols: String*): RelationalGroupedDataset = {
    val colNames: Seq[String] = col1 +: cols
    RelationalGroupedDataset(
      toDF(), colNames.map(colName => resolve(colName)), RelationalGroupedDataset.GroupByType)
  }

@scala.annotation.varargs
  def groupBy(cols: Column*): RelationalGroupedDataset = {
    RelationalGroupedDataset(toDF(), cols.map(_.expr), RelationalGroupedDataset.GroupByType)
  }