代码：

import org.apache.spark.sql.DataFrame
import org.apache.spark.sql.Column

def func(rawDF: DataFrame,primaryKey: Column, orderKey: Column): DataFrame = {

     //some process
    return newDf
}

我试图用上面的函数从现有的原始df创建一个新的已处理df。
代码：

var processedDF  = func(rawDF,"col1","col2")

错误：

<console>:73: error: type mismatch;
found   : String("col1")
required: org.apache.spark.sql.Column
   var processedDF  = func(rawDF,"col1","col2")
                                     ^

关于如何将函数参数的类型从string更改为org.apache.spark.sql.column，有什么建议吗